As to the poll question about Suggested/Recommended games....this is the single most important thing to me, if it is focused on retro games only. And so long as it does not morph into low-key advertising or monetization stream.
As a noob to retro gaming, having thousands of roms is the dumbest thing I've ever heard of. No normal person is going to play a thousand games and, more to the point, no normal person is going to enjoy trudging through that many games to find out what they like.
At most, what I really want access to is the best 50 to 100 games from across all retro arcade/console platforms, based on user reviews and popularity.
Now, yes this should be a feature the user can enable/disable. It should not ruin the user-interface experience. It should only add to the experience.
Also, I see no reason for this feature to be applied to modern games (console or pc). It only makes sense as applied to retro games. I don't need Launchbox to recommend modern games to me.