Heya, great theme! I have some issues that are probably more related to not being too familiar with Attract Mode, but wanted to check here:
Hi and thank you for the comments!
Most of the issues you are having are caused by the fact that Arcadeflow is tailored for use with MAME, so it gets the game data (categories, number of players, controllers, manufacturer) in a way that works with MAME and probably doesn't work with other emulators.
The same is true for the thumbnails and videos: Arcadeflow is designed to use game snapshots as main artwork, with the game title on top. And the orientation of the snapshot is decided from a property that I think only MAME games have (Orientation). If that property is not present the thumbnail is vertical (I should change that) but if you use box arts instead of snaps it will not work well and the artwork will be stretched a bit (to 4:3 or 3:4 aspect).
To make a long story short, Arcadeflow is not really suited for this use, I could try to rewrite some parts to be better when using console games, but right now it's mostly an arcade game layout.
EDIT: If you have game snaps (static, not video) you can use them as "snaps" artwork and Arcadeflow should work, but orientation will probably be a mess anyway :/ In that case I suggest using "Square" option