I would like to boot quicker by removing a/c I don't fly. Thanks in advance.

Just move them out to a safe place and try it, put it back if they don't work! I cannot really see it improving boot times in this instance though.

It's perfectly safe as long as you're not moving an object that something else depends on.   As long as you limit your pruning entirely to actual aircraft, the folders with the names of planes on them, and not any of the generics, you'll probably be OK.   I haven't seen any "actual" planes that reference another.   If there is one, you'll probably know it right away; something won't work, if it even loads.