all of what I mentioned before is still relevant. Giblits just make it look better.
UE2.5 has no way of animation inside the editor (save the movers that are different) Unless you want to make a lightsaber that does something other than being suspended in front of the character (no hand/arm models of it) then you'll need a modeling program, and animation.
To make it all work you have to know UnrealScript. Otherwise its like what is present already, a lightsaber static mesh, that does nothign and can't be inetracted with.
Unrealscript tells the game that you can interact with this object, and what to do with that object after you've interacted with it.
Also in the Clone Wars timeline, Lightsabers last of years at a time, so they wouldn't run out of juice. The older ones in Indecta Era were powered by blaster packs, but had a cord that ran to them.