JoeViking245

I presume "EmuMovies".  
After adding your EmuMovies credentials into LaunchBox and verifying it works (which you have done).. I think what you're after is
Tools Download Update Metadata and Media for All Games When you get to the LaunchBox images click Check None  Then for the EmuMovies click Check All (or just the ones you actually need)

LaunchBox is meant to be a keyboard and mouse application. 
Sounds like maybe the buttons are Keyboard Input (vs XInput).  A good way to tell is open notepad and press player1-button-5.  Does a "z" get typed?  If it does, also try this... (this assumes you have a Pause button...) Select a game.  Press and hold player1-button-1 and press Pause.  If all goes well, you just "pressed Ctrl+P" and the game should start.
This may not be ideal.  But again, it's intended to be a keyboard and mouse application. 

When clicking it (one or the other of the red arrows) it should open a dropdown menu (red box) to select from.  You then can scroll down to Platform Category (or Platform or Playlist or whatever you wish)

The issue I believe with TeknoParrot is, is that it's actually a launcher for the games.  So when you launch the "game", it then launches the "actual game" and quits itself.  LaunchBox sees the "game" is no longer 'running' (even though the "actual game" is still loading) and sees no reason to keep the loading screen up, thus closing it.  So even if you set the loading time to 20 minutes, it's going to close virtually right-away.
 
TeknoParrot (and also Steam for that matter) aside and keeping with this threads Title:
You can set it per game or per emulator for up to 30 seconds.
Per game:  Edit the game and in the Startup/Pause section, check Override Default Startup Screen Settings then click Customize.  Check Enable and adjust the slider as necessary.
Per Emulator:  Edit the emulator and in the Startup Screen section, adjust the slider as necessary.
Per many games:  Select the games you want to adjust it for.  Press Ctrl+E to start the Bulk Edit Wizard.  For the Field, select Startup Screen - Load Delay.  For the Value, adjust the slider as necessary.  Follow the prompts to save.
 
If 30 seconds still isn't enough, there's a plugin for that.  But it can only go to a max of 5 minutes.
 

With LaunchBox Premium, you can add an image to \LaunchBox\Images\Platform Icons\.
From there, go to the subfolder for which image type it is.  Platform Categories, Platforms (in your case) or Playlists.
Put your image in 'there' and name it exactly the same as the Category/Platform/Playlist. 
i.e.  D:\LaunchBox\Images\Platform Icons\Platforms\Windows Classic.png

It's probably not 'hanging'.  It's probably just doesn't have focus.
Edit MAME (in LB) and un-check "Attempt to hide console window on startup/shutdown"

It's listed outside the Consoles category and inside it. Just like how the checkboxes are checked. 
Un-check Root to have it be listed only inside the Console category.

K. That makes sense now.  In BigBox, System Menu, Options, Controller Mappings.  Map a button (or button combo) to Close the Active Window.  (NOT "Exit".  That exits BigBox.)  Use the button (or combo. whatever you assigned) when in-game, to exit the game and return to BigBox.
 
No.  Keyboard mode means the buttons and joy movements on the control panel are actually sending key presses.   i.e.  If I had notepad opened and moved player 2's joystick up, down, left then right... it would type out "rfdg".  That's the default MAME mapping for that joystick.

I believe what you did was edit the platform(s) and the (re)set the Folder Path for "Game".  When you add new games to that folder, that's when it will find new games.
To change the path for existing games, in LaunchBox, select all the games in a given platform ("system").  Then go to Tools < File Management - Change ROMs Folder Path for Selected Games...

Yes.  For the MAME emulator, just add a new emulator and point it to your mame.exe file.
For the ROMs, that's a little tricky, but it can be done.
For some [valid, I'm sure] reason, Ludlow saves the ROMs into folders named after each games ROM archive name.
So, to add one of those games to LaunchBox, in your Arcade platform,
Press Ctrl+N to manually add a file Give the game its Title Go to the Launching section Under ROM File, type or paste in the path to the "roms" folder then add a forward slash and type in the name of the games folder i.e.   D:\MAME-AO\0274\roms\flagrall Click OK to save and close wash, rinse and repeat for other games For the emulator's Command-line Parameters, you will need to add in -rompath %romlocation%.
 
As for automagically importing all the games, you won't be able to do that with way he had saved them.  To import, LaunchBox looks for files (vs folders).  And specifically for MAME/Arcade, it looks for .zip or .7z files.  You'd get to get more creative than what I mentioned above to be able to LaunchBox's Bulk Import Tools.

You need to un-check Auto-Populate to be able to manually add games to a playlist.
[If it helps] you can start with - creating the playlist using the Auto-Populate checkbox and filter(s).  Click Games to see the games that fit that filter. Go back to Auto-Populate, and un-check the box.  Click OK to save and Close.

Edit your UMK3+ game in LaunchBox.  Can you share a screenshot of the Launching section and also one of the Emulation section?

Depending on how you imported them, Super Nintendo Entertainment System (SNES) is typically a Platform.  SNES would then fall under the Category 'Consoles'.
What I think you're wanting (needing) to do is have your Famicom games into their own Platform.
If you can somehow manage to select just those games in your SNES platform, you can press Ctrl+E to start the bulk edit wizard.  Follow the prompts and then select to change the Platform and type in the new Platform name ("Famicom" or whatever you choose).
Alternately, remove all the SNES games and then reimport the [actual] SNES games and Famicom games separately into their own respective Platform.

The running scripts are only available as along as the 'emulator' (batch file, in your case) is running.  So if the batch file only Starts the process without the /wait parameter, it exits after the executing the Start command. Thus abandoning the Running Script.
So depending on what's in your batch file might be why none of the attempts are working.

Arcade machines weren't delivered in boxes.  They typically used wooden crates.  With that, you won't find [true] 'Box Front' images.  If anything, there should only be 'Fanart Box Fronts'.
For the Arcade platform, most people use 'Advertisement Flyers - Front' images.  Myself, I use 'Arcade Cabinet' images.  Neither of those are checked by default.

OK, so it's only closing BigBox.  That makes more sense.  
In BigBox, go to the System Menu < Options - Keyboard Mappings.  Look for the mapping for Exit and select it.  It should have an "X" next to it.  Press Enter on your keyboard and wait 5 seconds to clear it completely.
Alternately, while waiting the 5 seconds, you can press a different key to map as Exit [BigBox].
 

Click the stupid upside-down triangle to the right of Complete.  It'll open a dropdown menu in which contains other actually quite smart view options. Take some time to scroll through all the stupid view/filter options available to you.  When your done getting familiar with them, select the smartest one that says Platform Categories.  There you'll be able to see your "console" and "arcade" Categories.

If you used the MAME Arcade Fullset Import Wizard, there's an option to create a playlist for vertically oriented games.  If you didn't un-check that option, there'll be a playlist called Vertically Oriented Games.
If you had un-selected that option, you could re-run the Wizard.  However, if have you have curated your collection in LaunchBox, that's probably not a good option.
 
Alternately...
..and follow the steps outlined in this post.
Arrange game by Screen type? - Features - LaunchBox Community Forums
 

They look great when looking through standalone MAME and adds a little pizazz to it. 
 
Yes.  Within the Extras, the image files (at least) are all named after the ROMs filename.  So when placed into the appropriate folder, LaunchBox will associate them with their respective game(s).  The DATs and ini ("folders") files can't be used in LaunchBox without the use of third-party plugins.
The Multimedia pack does have soundtracks and videosnaps that would work the same when placed in the appropriate folder.  I'm not sure about their quality. (Not saying they might be bad. I just have no idea)
 
"Can I gain anything using those over what LaunchBox has available for Arcade Images?"
Not really.  When you download MAMEs Extras, you get everything.  Say you go to pull out just the cabinet images and place them in 'their' folder, you're putting in every single image [they have].  Whereas, when you download media from LaunchBox, you get only the images for the games you actually have.
If you have an EmuMovies account (highly recommended), the same thing goes for soundtracks and videos (get only the ones you need).
 
Images available on the LaunchBox Database (where they're downloaded from) are relatively complete for Arcade machines.  As are the videosnaps from EmuMovies.  Anything that is or may be missing, chances are, they're missing from Extras and Multimedia as well.

Follow this and just change Arcade to your NES platform.
 

LaunchBox doesn't have (and pretty sure never had) an innate YouTube scraper.  There is an older user submitted "YouTube Scraper" plugin that you would have had to manually download and install yourself.   Here's a link to the Support Page for that scraper.  But it appears to have been abandoned.  To remove it, just delete the folder/file you added to the /Plugins/ folder [while LaunchBox is not running].  
There is another user submitted YT scraper plugin call Vidsnap Scraper that is currently active.  If you're looking for one.

If you're talking about seeing them in the Main (middle) section...

Go to Tools < Options < Media < Box Front Priorities, check the box for Arcade Cabinets and then click Move Selection Up until it's at the top of the list. Click OK to save and close the Options window.
Click Image Group and select Boxes.
Moving it the top selection works nice because it won't interfere with other Platforms (as they typically won't have any Arcade Cabinet images).
 
If you're talking about wanting to see them somewhere else, please elaborate.
 

Since you have your ROMs and CHDs located in the /roms/ folder under your MAME installation:
In LaunchBox, Edit your MAME emulator.  In the Default Command-line Parameters does it have -rompath %romlocation%?  If so, remove it.

Not sure if this falls under a double entendre or an oxymoron.   
Merged          - (0.273) 76.54 GB
Non-Merged - (0.273) 141.6 GB
That is course is for the Full set(s) and you'd only be exporting some of those.  So "to save space.."?  In the end.. Probably not.  To have the export feature [more so] work in-your-favor and "Less chances of them not working and less headache"? Most likely.

That's all dependent on the core being used for that system.
 
Just looked back up at your RetroArch screenshot. For some reason Remove Quotes got checked.  Un-check that.