From what I know of birds, they can't survive as babies without their parents. Much like mammals, they require care until they are able to "leave the nest". Therefore, sending that egg off to a random location to hatch will probably spell death for its occupant :(
Not sure what else there is to do, though. Except maybe get out a ladder and put the egg back? Don't fall!
They can if you feed them. I wont put it back that nest is bad it will just blow out again.. Will try incubate.. There are certainly no shortage of weavers in the area. They rip up the bosses Palms :P Cheer$;)