Yes, UC's always takes the highest SAT score, but they will see both scores.
There's no rule saying how many times you can take the SAT, you can take it as many times as you want. However, in my opinion I think a max of 3 times is best. Taking it too many times make it seem like you are devoting too much time to it. Kind of overkilling it. Again, that is just what I think, but if you think you got a chance for a big improvement...then take it more than 3 times.