you recognize that you need to take upper level sciences (and sounds like you will)...then you say you can't afford to take them at UW. so where do you plan on taking them? because taking upper level sciences from a 4-year institution is going to be a strong statement to make to dental adcoms.
UW doesn't require an anatomy class, if that helps your pocket. Other schools might, though, but one quarter of physiology could be enough, just make sure you check other schools' requirements.
Your GPA isn't too bad and your DAT scores are great. As someone said earlier (and you said you are aware of it), your classes at a CC could be a set back and it's bound to come up in an interview as to why you took most of your classes at a CC (you seem to have very valid reasons though). I do think it would be a good idea if you took the remainder of your science classes at the UW to show that you can handle university level classes. Take as many as you can afford - it can never hurt to do well in upper level science courses.
As for finding a job/volunteering, I'm not aware of a dental related job that pays around Seattle for inexperienced individuals (unless it's part of work study)... Well, I never really looked. You've said that you've done some volunteer work at the dental school. What were some of your tasks? Also, have you done any volunteer work that wasn't dental related?
If you want to talk more in private, feel free to PM me.