The Surface Pro 3 is just a Windows tablet, so long as you have a model with the power behind it you should be fine. This goes for any other machine as well, as long as it's Windows based.
Games and Emulators can be anywhere you like (hopefully that was shown in the video's) including over a network or OneDrive. Even if guides are for older versions it should be mostly the same unless they've changed something significant. The last big significant change was when MESS was integrated, and even then nothing changed besides the combination. For the most part, revisions to the emulator just change what games can be played, usually. So if you add the emulator, then tell LB where your MAME games are, and use the MAME import process you should be good to go. Now granted, MAME is super tricky and confusing and even LB doesn't handle it all that well.
For importing MAME the easiest way possible though I do suggest using this: https://www.launchbox-app.com/forum/emulation/lightspeed-ultra-fast-mame-importer-tool#p13904
We are even working on integrating it in to LB in the future.