Equity Trader Requirements/Perks?

I’ve heard from a friend working as an equity trader that if you have a 7 you get some capital exemptions and reg t waivers. (Much more than 2:1 leverage.) I’d always found it odd that one needed any license at all to work at a trading firm but suppose this makes sense. The 55 seems to be the main relevant exam, which requires the 7 as a prerequisite. Can someone cue me in on the requirements/perks of someone who wants to work as a licensed equity trader through a firm rather than alone?