Hi! I was in a band throughout college, and was in a different band part-time when I taught elementary school. You're right - being in a band is all about being a team player. I've seen many bands fall apart because of one person having a big ego. However, it's a really rewarding experience if you're willing to put in the work. Having lots of rehearsals are hard and time-consuming. Being on the road for a tour is not glamorous - you don't eat well, you don't sleep well, and it's easy to have a short temper because you're around the same people all the time.
That being said, the feeling of being on a stage and playing your part, knowing that it sound really, really good, is a feeling that I wouldn't trade for anything. So, I would recommend playing part-time - if you're interested in being an entrepreneur, definitely go to business school while you're working on your music on the side. That way, if being in a band isn't what you were hoping for, you always have a back-up plan. Plus, one thing about playing in a band is that you can't do it forever. Indie rockers in their 40s always seem washed up. You still want to have a life after you'd had your rock career.