Much of the difficulty of moving across the country for a job is negated if you have strong ties to the area, for example you're from California and your family is there. Plus, BU isn't a "national" school like Harvard or Michigan or Cornell, but it's right there at that next level, and it's not half bad in California. And second-guessing I think is normal. Stick with BU!
I largely concur, although I don't quite know what you mean by "national"; BU has grads all over the country, although most of our graduates do tend to prefer the northeast, New England, etc.. BU has a great name that travels a lot of places, including CA. There are quite a few people here from the West Coast, many of whom fully intend to go back after graduation. As halfie points out, you already have strong ties to CA, so the most important thing to do from a placement perspective is to maintain them; this basically means getting summer jobs in CA (as a couple of my classmates are doing) and making connections in the legal community there. I don't think you'll have any trouble getting CA employers to hire you with the BU line on your resume, and they certainly aren't as likely to pose the "Why CA?" question to someone with your background (compared to, say, the kid from Brookline, MA, who has a BU degree).
But ultimately, it must be a decision you're comfortable with, and if staying closer to home is what you think is best for you personally (Davis is a great school, too), then that's what's best. But we'd love to have you, if you're willing to have us.