JoeViking245

The error indicates something is up with your license file. Email support@unbrokensoftware.com and they can sort it out for you.

If you have the ROMs/games loaded into RPCS3 already, you can turn on the Auto-Import feature for the platform and LaunchBox will read RPCS3's virtual drive and import those games.  So in this instance, no. It doesn't matter where you store them.

View < Media < Refresh All Images

 
Alternately, you can click on one of your PS2 games then press Ctrl+A (to select all games).  Then press F5 to refresh images for selected games.

In that case, in LaunchBox, Edit the game you want to change the default version to be played when you click Play.  When editing that game, go to the Additional Apps section [for that game].  There you'll see the different versions of that game.  [Single-]click on the games' version you want to set as default.  On that same screen, click Make Default [located on the bottom right of that screen].  Click OK to save and close the edit window.  Now when you click Play, that version you selected previously and had clicked Make Default for is the version that will be launched.

Auto-Save, 'Manual'-Save and Quick-Save are separate Save States.  The Error is trying to load a Quick-Save. (vs. creating one)
Open MAME (mame.exe) and go to General Settings < Input Assignments < User Interface and look for Save State to see the assigned keys for saving and loading States.
[The default] to create a Save State is F6.  (To create a Quick-Save, it's Shift+F6.)
[The default] to load a Save State is F7. (To load a Quick-Save, it's Shift+F7.)
 
Here's the 3 different Save States

"1" is a "manual" Save State. (I believe can be a number 1 through 9 [1 through 0?].) 
"auto" and "quick" are self-explanatory.

Oh snap!  I was thinking save states.
For per game configurations, you'd use  -cfg_directory "
"D:\MAME\mame.exe" nes -cfg_directory "D:\MAME\cfg\nes\addfam" addfam Or
nes -cfg_directory cfg\nes\%romfilename%  

Correct.  BigBox is not setup to manage your games.  Just looks pretty and plays games.

Looks like I missed saying to uncheck the "Remove quotes" and also the "Remove file extension..." boxes.  Srry 'bout that.

In FinalBurn Neo: Misc < Configure ROM paths...    Set the path to your ROM folder(s) [if not already]. In LB, edit the emulator and check the boxes Remove Quotes and Remove file extension and folder path. At least that's what worked for me. I got the same error with those 2 un-checked.
 

Un-check Remove Quotes.
Also, add --nogui to the Default Command-Line Parameters.

MAME is for Arcade games.  Appears you had imported them into the Windows platform (vs the typical Arcade platform).
By default, LaunchBox sets the metadata/media scraping for Windows platform to Windows [PC Games].
If you wish to keep your Arcade games in the "Windows" platform, edit the platform and set the Scrape-As value to "Arcade" and re-scrape the metadata/media.
A more prudent approach could/would/should be to remove all the MAME (Arcade) games from the Windows platform and then [re]import your MAME ROMs into the Platform "Arcade".  Then when you download images, you'll get the ones for Arcade games and not PC Games.

I'm fairly certain your "mame64.exe" is from an older version of MAME.  Being older is not the issue (and nothing to be concerned with). 
However, having the command-line parameter -keyboardprovider dinput would be an issue with older versions.
Edit your MAME64 emulator ('Edit/Bewerken' from screenshot above) and try removing that and see if it [now] works. 

If it's showing when LaunchBox is first being started (aka when 1st launched/loaded), I'd say LaunchBox is [still] attempting to load an eXo ('exodos stuff') remnant.
Assuming you're starting it via LaunchBox.exe (vs. a batch file or script), look in Tools < Options < Startup Applications and see if there's anything eXo related.  If there's nothing in there, I'd next look in the /LaunchBox/Plugins/ folder.  Not sure exactly what would be 'eXo' there.  But those 2 locations should/would be the only places LB would start something extracurricular (aside from a batch file or a script that starts LB).

If, when you disable G-Drive syncing and you're happy with how LaunchBox/BigBox performs via G-Drive (which I guess at this point is actually running from your local G-Drive folder), then...
 
A variation of a Google search result looks like this:
This link mentions "googledrivesync.exe" which is now "GoogleDriveFS.exe" (at least on my PC). It seems there's no command-line parameters you can pass to the executable to turn G-Drive syncing on/off.  So you have to "kill" the process. From the Windows Command Prompt, to kill G-Drive altogether, you can run taskkill /IM GoogleDriveFS.exe /F Then to restart it, double click "GoogleDriveFS.exe".  Mine's located in "C:\Program Files\Google\Drive File Stream\100.0.2.0\"
 
LaunchBox/BigBox has a Startup Applications feature that can load an application when one or the other or both (or neither?) are started. (Which could be a batch file containing the above command.)
But there are no (immediately accessible) means to launch an app when either close.  "Immediately accessible" meaning, you could create a plugin that captures the System Event LaunchBoxShutdownBeginning and/or BigBoxShutdownBeginning and then (re)start the process "GoogleDriveFS.exe".
 
Alternately, you could create/use a batch file that handles the whole kit-and-caboodle.  Something like this (edit accordingly)
taskkill /F /IM GoogleDriveFS.exe timeout 5 start /w "" "D:\LaunchBox\Core\LaunchBox.exe" start "" "C:\Program Files\Google\Drive File Stream\100.0.2.0\GoogleDriveFS.exe" Do This:
Verify YOUR Google Drive executable is indeed "GoogleDriveFS.exe" Change the path to YOUR LaunchBox location DO point to the /LaunchBox/Core subfolder Change LaunchBox.exe to BigBox.exe if that is your preference Verify that is the path to YOUR "GoogleDriveFS.exe" If all's good/tested/working, make for a 'prettier' presentation...
Create a shortcut to the batch file Right-click the shortcut and select Properties Change Run from Normal Window to Minimized Click OK to save and close. Use the shortcut to start the "whole kit-and-caboodle".  The above makes it so the Command Prompt window does not appear.

The only times I've seen this happen is when I launch the game, and it's the 1st time Steam has been launched (on that particular day), and Steam has an update.  Steam will do its update thing and then show the "On Sale" and 'Main' windows.  This happens in the background, so you don't see anything when the game [eventually] starts, and you play it.  It's when you exit the game you see those windows still lurking [on top of BigBox].
I've gotten in the habit of, before I start BigBox, if I know I'm going to be playing a Steam game, I'll
Start Steam 1st.  Let it do its thing close/minimize Steam when it's done then start BigBox.

For this, you'd need to create a plugin (written on C#).
Essentially, it'd catch a selection change event, determine that the change went into a playlist (vs say a different game, a platform or a platform category) and that the playlist is 'your special playlist'.  From there, execute what you wanted done.
 

In your Flycast emulator folder, edit emu.cfg and set fullscreen to yes. 
[window] fullscreen = yes  
In LaunchBox, edit your Flycast emulator. In the Running Script put:
$Esc:: { WinClose, ahk_exe {{{StartupEXE}}} }  

I presume those folder names look similar to Platform names.  (That, or exactly like platform names.)  They're auto created when you have auto import enabled.  (For games. Not to confused with the auto import for storefronts.)   This allows you the proper folder names to drop your ROMs into to have LaunchBox import them from.

The keyboard shortcuts listed in that link are for their "LaunchBox" (referred to as "the LaunchBox").  Not to be confused with (this) Unbroken Software's LaunchBox.
You can Tab through the panes and then arrow Up/Down in the respective panes. Still, it's pretty 'clunky' that way as [the Real LaunchBox] it's meant to be a Windows based keyboard and mouse application.

View < Show/Hide - Text on All Games (or Ctrl+Shift+T).  But it won't show the File Names.  Just the Game Title.  

The games File Name can only be seen in the Game Details [right] panel.  To enable showing those, go to Tools < Options < Visuals < Game Details and check the box for File.

Yes and no. Those are 2 different licenses.  But there is [limited] free use of the Android app.
Download LaunchBox for Android
Free for 100 Games or Less
LaunchBox for Android is now free if you need less than 100 games. For an unlimited number of games, you can easily purchase a DRM-free license. But you might as well download and try out the app for free, first! It's super easy to install the license after purchasing, and it does not require a reinstall.

When in the Arcade platform, press Ctrl+N.  Type in the games Title.  In the Launching section, Browse to where the ROM is located and select it.  Click OK to save.
If it doesn't appear in with your other games, make sure you don't have 'Hide games missing media' (worded something like that) checked.  It'll be in the View menu.

In short. No.

To set the default images used for your platform, in LaunchBox:
Got to Tools < Manage < Platforms Select your platform  Click Edit (the easy way) From Windows File Explorer,  Select your image(s) drag and drop them onto the area below where it says Images Use the left and right arrows ('carrots') to switch images Click on the image type to change,,, well,, the image type. Once you've set them, click OK to save and close.

No.  LaunchBox calls AutoHotkey.exe directly from its /ThirdParty/AutoHotkey/ folder.  So you're safe to (re)associate your .ahk file extension to your personal installation of AutoHotkey.
 
Side note: you don't have to have it "installed" to be able to use it. 
i.e. You can launch your script directly like so...
"D:\LaunchBox\ThirdParty\AutoHotkey\AutoHotkey.exe" "D:\MyScripts\My Special Script.ahk"