Few people would consider Pomona the seat of a great college experience the OP mentioned. The campus itself is nice, however it isn’t in a very nice area and is primarily a commuter campus.
This seems like a poor plan, IMHO. If your parents are willing to chip in so you graduate with little or no debt, that’s one thing. Taking on a lot of debt, which is what “work together” implies to me, is a poor idea when you have lower-cost instate options. The odds of graduating with a CS degree are probably similar to those of entering engineers, which is around 1 in 2 or less. I’d say the lower end if you just think you’re going to get a 3 on the AP CS test. If your heart was really in CS you’d be studying it as much as you could and writing your own projects “just for fun” on the side; certainly in college you’ll have many fellow CS students doing just that. Best case you graduate with good grades in CS and a lot of internships under your belt, ending up with great job offers. In such a case the debt burden wouldn’t really matter. But you need to be willing to consider the case where you find out CS really isn’t your thing, if you go OOS you’re at a school running $25K or more a year in costs after that $15K scholarship you have, in a degree that may not pay all that much when you finish.
Pomona, by process of elimination, is your best choice. It’s instate, costs are lower. They admitted you to CS, so if you get off to a rocky start you are still a CS major. Have a rocky start at SJSU and that will keep you out of the CS major.