For 1, yes it will look bad, a lot of students at the university I attended would take Physics I and II at the local CC because they were afraid of doing bad.
For 2, most Dental Schools do not accept pre-reqs from CC's. If you already have a school in mind it would be worth it to check but i'm sure others can vouch that you must take your pre-reqs at a 4-year university.
Not true, in fact, the opposite is almost true. There are a number of schools that won't take CC credit, this is true, but it's less than 10, probably less than 5. I know I must seem like Mr. CC Defender on SDN, but yeah, I took all of my pre-reqs at my CC, and other than the minor slap on the wrist of, well, we would have preferred you take them at the 4 year, it wasn't a problem (minus the schools that really don't take CC's, like Temple or Tufts I think, which I didn't apply to accordingly).
Anyways, to the OP, it will look a tad odd that you took all of your other pre-reqs at the 4 year, and only Physics at the CC, so if you can, I'd suggest taking it at your university. If it's absolutely impossible and a total hassle, go ahead and take it at the CC, it won't be too bad, but be prepared to answer questions about this at your interviews. If you started at a CC, well, you started at a CC, but if you started at a university, as stated above, it can look like you're just trying to avoid a really hard teacher or something - not to say that CC classes are always hands down easier or less challenging, as they're not.
