As for the ethnic diversity of So Cal..... Well, that is all too common from an Americans
Since Kev is coming from the UK I doubt that's going to be an issue as they've been living in that sort of highly diversified environment for decades. In fact, when I moved over here to the Seattle from Oz, I was surprised at the lack of cultural diversity. The opinions like those expressed above are, unfortunately, rather typical for this part of the world. - even in such a diversified place like Seattle with all the high-tech imports here.
As for getting a job. It's going to be close to impossible for you. Firstly you have to get a H-1B to be able to work. Even if you're coming over on an academic visa, you won't be able to work for any other company unless you also have a H-1B. Considering that the 04-05 quota is already completely filled, you'll have a very tough time getting hold of that visa.
As for rent managment with a foreign house, I've had no problem with it. I own a house still in Oz that I rent out. So long as you have a decent long-term tenant there, and a decent rental agency to worth with, it's almost set-and-forget territory. If you want your house to be in one piece when you get back, insist that you get long-term contracted tenants in (ie 12months plus).
Length of time here before requiring to return is 6 months on a tourist visa-waiver program. However, if you want to get paid at all, you're screwed. You must be on a proper working visa of the appropriate type. If you're going to be doing research at UC Davis then get hold of an academic visa. They're a hell of a lot easier to get so long as you have the university back up your claim - that is, you pretty much have to have it in hand before you get here.
If you're not sure what is going on, then come over on a tourist waiver for a "holiday" and make sure that's what you tell the INS people when you get off the plane. Don't tell them that you're looking for a job or anything remotely like that. They'll have you rejected and on the plane back before you can blink. Wander in and chat with the uni and see if the position is a goer. If it is, get the uni to line up the paperwork and then go hit up INS for an academic visa while in-country. You'll get all sorts of waivers to stay here while they process the paperwork, and it's likely the uni will have a legal department that can take care of it pretty easily for you. After all, they have a fairly large foreign-student program that they deal with all the time, so they know what they're doing.