Re: Getting legal
getting legal in CA is pretty simple. the plate and the dot helmet is the main thing to look legal.
you can get a M1 permit at the dmv. good for a year.
there's a few good thread with all the legal info, just use the search box.
as far as mileage, you should be able to make it to the beach and back if you have the larger tank. i went from costa mesa to belmont shores and back with fuel left over.
my bike averages about 70 miles to the tank. it can vary wildly, depending on headwinds, hills, and traffic.
long trips i usually bring some extra oil, gas it up at the pump and shake the bike around to mix it.
and yeah, watch out for newport. those cops don't mess around.