Spent 3 years in AA. Inspectah gave some pretty good advice.
Zingerman's (not the Roadhouse) is an absolute must. One of the best delis in the country. I know it sounds dumb, it's a deli. But it's basically one of the best sandwiches you'll have in your life. My advice would be to go on Friday night or first thing Sunday morning. With it being a game day, it's going to be slammed on Saturday, i.e. you'll be waiting in a very long line outside for a very long time. Zingerman's pastrami is better than Katz's in NYC. I've had both in a fairly close time frame. Katz's is great but I give the nod to Zingerman's on an objective basis.
Angelo's is good. But I wouldn't call it a must. There are a lot of really good brunch options in Ann Arbor and I wouldn't sweat any one in particular. Afternoon Delight, Cafe Zola, Broken Egg.
https://detroit.eater.com/maps/best-brunch-breakfast-ann-arbor-michigan
I highly recommend you try to go to the game. $150 sounds about right. IU is not a big rival, UM is pretty much assured a win, so it's not like you're going on MSU, ND, or tOSU weekend. A lot of life in AA, particularly in the Fall revolves around Michigan football. And it will be a great to experience that while you're there. I'd recommend you get down there early and take in the tailgating experience, even if you're just walking around. North and East of the stadium is where most of the students are. South of the stadium on the golf course is where most of the alumni or just regular hard core fans are. The tailgating is really established over there. Big screen TVs, smokers, etc.
I could recommend various bars, but that's probably not on your trip agenda.
Skip the Brown Jug entirely. It's just a campus dive bar/restaurant. Not really notable. Although Eminem did a surprise performance there one night when I was in school on a gameday weekend. And it's also where Jim Harbaugh purportedly bought a burger for a recruit that has now brought the NCAA's wrath. It's worth walking on the street where the Brown Jug is just because it's a main street for the college with lots of student life.
Regarding campus, I think the law school is basically the nicest part. I don't think the campus overall is as beautiful as Wake's. However, the law quad is amazing and the new business school next to it looks very cool and modern. The rest of campus is kind of a big school in a small town, which means it has a lot of amenities, i.e .bars, restaurants, etc. I never spent any time in the Greek houses east of campus but some look amazing.
Feel free to reach out with any particular questions.