When you take it apart, don't lose the lid springs. It is easy to do, and then that sucks. Also, don't overtighten the screws around the feedneck piece.
If you want more speed, get some 9.6 volt rechargable batteries. This will reduce the motor's life, but your egg will be really fast.
Grip tape on the lid makes it easier to open with your palm. File a bit of the snapping edge from the lid to make it open easier, use spring tension to keep it closed.
To cut the neck down, put an old cocker barrel in the neck and use a copper tubing cutter to cut the plastic evenly. Watch to make sure the cutter doesn't jump from it's groove as you cut. The old barrel is to keep the neck rigid and round, instead of deforming and contributing to the cutter turning off track.
Or just leave the thing alone and play, it is a low maintainence piece of gear that you shouldn't be messin' wit! Wipe er off once in a while.