The only issue I could see with composite is weight. The bees won't care one way or the other.
Didn't think about weight. It might be a little bit heavier, but I already thought of physically moving hive as a two person job (when occupied). I'm sure if I tried to move it by myself the webcam would yield a horrifyingly entertaining video on youtube.
It depends on the quality of the water. Adding a splash of clorox seems to lure them fairly well. Ten feet might be a little too close for them, though boardman feeders filled with water also work well.
What is a good distance for a water source? I haven't purchased a bird feeder/water source yet.