I'm probably not the right person to ask these things.

The game doesn't have official controller support, according to the Steam Store page, so you'd have to map controller buttons to KBM. There's a guide on Steam, so I guess you can play it that way, but I don't know how good it is.

As for the rules, I've only barely scratched the surface for anything D&D related, so I can't really know or compare. To me, it's complicated, but it offers more information about everything. Keywords in tooltips are highlighted, so you can either click or mouse over, for further explanation about something. There's a log, that can show rolls, but I've barely used it. RTwP with often 10+ characters in a fight, there is just so much spam. The basics for 5e from BG3 felt extremely easy to understand, even for me. Just like BGEE, I'm going through PoE basically higher number better (ignoring that THAC0 stuff in BGEE), and it's working, although with lots of save scumming.