We went the first week of March a few years ago and I thought it was a pretty good week to go. The crowds weren't that bad. I don't remember waiting in long lines. I do remember we walked right onto to Tower of Terror. Also I didn't make any PSs before we went, we made them the night before or the morning that we wanted them and we got into the everyplace we wanted to eat.
Weatherwise - our first day was about 80 then a cold snap came through it went to 40! We wore our winter coats for 2 days and then it went up to 60s and our last day there were people in the pool when we were heading to the airport.
I don't remember the hours.