As long as you can see the gameplay with a decent quality, I dont see any problem.

There’s some pretty cheap ones on Amazon I got one for 14 bucks

Typically you don't really need a capture card to record runs, but make it at least viewable. But like mentioned, there are cheap cap cards to buy online.

Idk, but what’s your hardest in gd @D2agon

a keyboard is as far as I know allowed under certain categories

keyboard and mouse is allowed, but ur kinda cringe if u use it

@D2agon cool mine is Chroma by Renn241