No, but you better ditch brave and set up Firefox. They did some shady shit in the past and tried to deny or cover it up.
Mulch, focus on security (same as Bromite), OE Mull, focus on privacy, both can be installed from F-Droid
Not sure why you're getting downvotes because you're essentially correct. Their adblocker is written in rust and they say it's based off uBO.
Depends on what block lists you use and how aggressive you want the filtering to be. I've been using Brave for a while and tested it with and without uBO. With Brave Shield set to aggressive blocking (what I higly recommend) it blocked about 99,5 of all the stuff uBO would block.