Check the times and your schedule
There is no problem playing in multiple events as long as you make sure you have no conflicts between the two (or maybe three). I actually like the idea and do it whenever possible. Lets say you only sign-up for the Venetian and are the first one out after 8 hands, this gives you another event to play in for sure.
The Venetain is scheduled for 12th - 15th, so registration will be on the 12th so play should start on the 13th and if your still in the 14th.
The Golden Nuggett and Imperial Palace both will start registration on the 13th with play beginning on the 14th and 15th.
The best combination would be to play the Venetain and Imerial Palace events because of how close they are, but make sure what your schedule is at the Venetian for your round (if your still in, hopefully you are), when the Wild Cards will be called, and when the later rounds are scheduled. Then you can check on playing one of the other events and schedule your 1st round inbetween the Venetian.
If possible schedule your first round in such away that you may be able to play a re-buy at GN or IP if needed as well.
At most places you can get the starting time you need if you just ask them nicely. I do suggest you get to the registration early so you can pick the time you need.
Good luck, at whichever events you play.