Re: Weak Tree
I think you just got yourself a bad, sickly tree. Saplings are usually much stronger and more flexible that what you describe, even for a hardwood like a walnut or oak. I'd yank that thing out and replace it.
What to replace it with would depend on what you want the tree for and the conditions and zone in which it's being grown. For shade I'm partial to maple or little leaf linden. Both grow fast and have a nice canopy.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!