Im confused, in your first post you talk about moving everything back (insisting that its nose heavy), in your second post you talk about leaving it tail heavy... which is it, nose or tail heavy?

A little nose heavy wont hurt anything, if its tail heavy you will want to try to get it as close as possible to the CG. If its too tail heavy it wont fly good at all... I have seen planes almost uncontrolable from being tail heavy.