There aren't any chapter houses at USD and they weren't at LMU (where I went) but that doesn't mean the Greeks are on life-support or anything. You just have un-official houses or apartments and party elsewhere...works out fine, especially if you don't transfer from a school with houses. Also avoids a TON of problems!
I don't think UCSD has official chapter houses either. It's usually a neighborhood ordinance or similar situation. That was the case @ LMU.
The Latino/Hispanic Greeks were growing at LMU when I graduated (2000) and we had strong AKA and Alpha Phi Alpha chapters.
Occidental just colonized their first Panhellenic sorority (Theta!) but they still have mostly locals, with a few IFC fraternities (ATO is one, I think).
Not sure about multicultural groups at USD.
Since you'll be in grad school, I suggest holding off a bit on starting a chapter. See if you have time. Maybe there's a chapter near where you'll be & you could be an advisor or organize alumni events?
Boston...great place to visit, wouldn't want to live there...mostly due to weather. I have family there & my nephew is a Phi Sigma Kappa @ MIT. While it's historical, super-urban, etc, there are still stuck-up people (smart & stupid ones) and plenty of non-working class folks. My sister & bro-in-law included...a Cal Berkeley & MIT grad...not blue-collar or anything like Good Will Hunting.
Good luck with whatever you choose!