Other than not paying CSU tuition, I don’t understand how that is any better than taking the courses at CSUN.
You note you are looking for a college experience and a decent CS program - that’s what you have now. All you need to engage in the campus, join clubs, pledge a frat, go to campus events and hang out on campus - you’ll find less of that at most CCs as most students view them as transitory. As a 4 year student at a single campus, you have a chance to get multi-year internships, multiple leadership roles in clubs, etc. That will make the place feel like home and can really set you apart in the job market. If you attend 3 schools in 4 years, you simply won’t have time to set down the roots needed for the classic college experience.