Don't worry about phase closures in Epcot, you'll definitely get back in. Some tips? Visit the dance parties. They really are awesome! Lines for food and drinks are going to be extremely long so if you think you'll get hungry maybe pack some food or be prepared to wait. Also, don't leave right after fireworks. Wait maybe 10-15 minutes to let the masses leave. You also might be able to hop in line for a ride on your way out if it's still before closing and there aren't long lines then. Have a great time!