I wrote up some of the info I've gleamed as a liveaboard for the last few years in San Diego, including doing an hour audio interview with our marina manager. Boring as hell for anyone who isn't interested in hearing about marinas and managers.
Rebel Heart - Sailing, cruising, liveaboard blog and website - Eric's Blog - How the liveaboard thing really*works
In short, it really varies by marina and even the ones who are pretty lenient will never outrightly say they are because then they'll get abused by the jerk residents that the rules are there to keep out. A good marina does a good job of flexing the rules to allow the non-problem boaters to have fun but enforces them to keep the jerks out. It stinks having a double standard and "read between the lines" rules delivered with a wink, but it works.