Can vouch for 8bitdo, I've only used them and they're very good. Currently have 3 that I rotate around

https://smile.amazon.com/8Bitdo-Gamepad-Nintendo-Windows-Raspberry-pc/dp/B07R481CVY/ref=sr_1_16?dchild=1&keywords=8bitdo&qid=1610250299&sr=8-16

Yep :) although remember they're great for practice.

Not Banned. You're good to go. All official releases are fine.

First off, Welcome Setup looks good, I started with the same setup. Using a Standard Emulator is Fine. SNES9x 1.60 or Higan is accepted so you're good there. Xbox Controller will work fine, but you'll quickly outgrow it. Since you're on PC i'd look at a 8bitdo SN30+, it has a proper D-pad

All in all, you're looking good. Go grab Livesplit make some splits and start running