I go to IU, so I can speak for the school! Kelley is a highly recognized business school. It is competitive in job placement and has an amazing alumni program. My friend is graduating this year with a degree in Kelley and he has had paid summer internships in Chicago & now he has a job with them; starting pay: $80k.
Basketball is huge here, yes. The atmosphere is really great and spirited. It’s obvious that the students here are huge fans of IU sports and other organizations! Hoosiers have passion. Sports are a huge part of campus - the Little 500 race was just this weekend, for example. Football, basketball, etc. are all well-attended. But there are plenty of others things to do as well. The music school always has performances & organizations on campus are always putting on events. You will never be bored! The campus is also beautiful. It’s pretty big, too, so there are plenty of spots to discover. I love the fall here as the leaves are changing - it gets even more beautiful!
AP credits are a lifesaver. I came in with over 30 credits, which made me have sophomore status. However, you should understand that not all your credits will come over - each school is different, and I know Kelley is more selective. I can’t speak for IB, but my friends with IB credits seem to also be ahead of the pack in credits.
I have to disagree with your statement of IU not being diverse. IU is very culturally diverse. I have friends who are expats living in Saudi Arabia and Japan, students who came here from Vietnam, England, Spain, France, China, etc. The town of Bloomington has a nationally-recognized international food scene. Fourth street has restaurants specializing in foods from Afghanistan, India, Italy, Czech Republic, Croatia, Thailand, etc. I lived near a big city for high school, and Bloomington still amazes me as just how diverse the school really is. The school is diverse in others ways too, such as events and organizations. There is something for everyone here!
Furthermore, yes, Bloomington may seem like it’s in the middle of nowhere. But the town of Bloomington is much bigger than expected with amazing restaurants and shops. Plus, you’re only an hour away from Indy, less than 2 hours away from Louisville, and about 4-5 hours from Chicago. You’ll have access to major cities right at your fingertips. There are many forest reserves around the area, too.
Greek life is quite dominant at IU. However, not everyone does it. That’s a misconception. In fact, only 30-something% of students join Greek life. I am not in Greek life, and most of my friends are not either. I have a few who are, but they enjoy that lifestyle. It’s not for everyone, that’s for sure! I have never felt pressured or less than or disappointed in my school decision because of the heavy Greek presence, so don’t base your decision off that! I’ve never been annoyed by its presence either. I have been perfectly successful in finding friends and things to do without joining Greek life, as have all my friends.
Partying at IU, though, is really popular. But, again, if you don’t want to, you don’t have to. There are things to do every night on campus, and going into town is really fun, too! No matter what school you go to, though, partying will be present lol! I live in the Southeast neighborhood and haven’t been awoken by parties or bothered in any way. If you lived in the Northwest neighborhood, though, that might happen. It’s really up to you if you decide to surround yourself in that environment. 
IU is a prestigious school - it’s considered a “public Ivy.” Yes, the acceptance rate is high, but it’s also a state flagship. What you do during your years here will determine your future, not the prestige level of a school! That being said, Kelley is a very prestigious schools and have recruiters from all over the world interested in Hoosiers. Target, Deloitte, and Cook Medical are just a few big-name companies that have a huge presence at Kelley. As I mentioned, immediate job placement is high & the connections made within Kelley are everlasting. You may also want to look at the 3/2 Bachelor’s/MBA program in Kelley. You get a Bachelor’s & MBA in 5 years! It’s pretty popular in Kelley & in other schools on campus.
I would definitely take a serious look at Indiana University. I’ve really enjoyed my time here & I’m looking forward to the next years! There are so many opportunities and I’m grateful for all the help I’ve received.
That being said, both schools are great schools and you can’t go wrong! Obviously I’m biased towards IU, but I hope I was able to help. If you need more answers, I would definitely message an advisor in Kelley or Career Services. They may be able to give you more insight. Best of luck in deciding!
He also said that freshman gen ed classes were huge and there were a lot of distracting freshmen, most of whom “disappeared” by sophomore year.