sorority rush as a senior

All houses but two or three would drop you first round. No house wants a senior unless they are desperate for members. There's no investment for them except your dues for one year. There would be no real friend group for you as a senior, all the juniors and seniors already have their groups and you would be in a new member class of 18 year olds, would you want that? Even sorority members start kind of mentally checking out their senior year because they've done it all and are thinking about life beyond school, so they're not around much.

No. A sorority has no reason to offer a bid to someone who will only be there for a year, whether you're a senior or a junior who's graduating early. They are picking members based on what's good for their house, not on what you want. And you being 20 is much more about your experience being in a NM class with a bunch of freshmen 18 year olds right out of high school and you having been in college for two years already. There is a big maturity difference. Unless you are already in a friend group with members your age you aren't going to get close with any of them. They already bonded with each other and found their close friends when they were new members.

DPhiE, SDT, AXiD would be your only options.

Are mean try. Any house would be fun if only for a short while

Your chances will be a lot better with more houses if you list yourself as a junior. Can you do that? Go for it. Good luck.