That actually sounds pretty rushed to me, especially for the LA side of things. If you just want to do Disneyland, then OK but there is so much more to see. Also, you are going to completely flip your body time-wise, and so you could get some major jetlag in there and with only limited time that could spoil things a bit. To be honest I wouldn't be going for less than 5 nights in LA if you can stretch that far.

Three nights in Vegas is ok. Hawaii would be a nice way to break your trip on the way home and 3 nights will be fine. Of course, 3 weeks in a tropical paradise would be good too ;-)