Those are all valid concerns. I have heard that Ohlone is not a great program, difficult instructors. SCC was truly a great experience and now that I'm working, it's all coming out for me.
I lived 45 miles from the school when I went, which was a drag but doable. Some people commuted from farther away which was difficult. some people found a place to crash during the week since classes were generally 3 nights a week and they went home on weekends. Since the school is relatively less expensive than Carrington, I would just consider that part of your school expense.
Carrington is a newer program, probably not as organized. SCC has been here since the 1990s and the director has streamlined and makes improvements each year. nothing is perfect but it's a great program. And, during clinicals, they try to find you a place near where you live (doesn't always work) but there are probably more choices in the Bay for that. It could be doable for you if you get creative.
Competitive.......yes. everyone is going back to school now. last year there were at least 400 applicants for 30 spots. but it doesn't work on a points system, it's a lottery and based on how many times you apply. as long as your grades were above a C in the prereqs and all classes are completed, you're in the running.
go to an informational meeting, they have then first Thurs each month.
PTA 101 is not transferable. SCC PTA 101 does have an online class that you only show up for one or two classes.
Good luck. get creative and see if it's something you can do. the drive is not great but if you stayed over 2 mights a week in Sac you could do it and have even more time to study.