Can I delete folder Developer-3.2.5? [duplicate]
Yes, you can absolutely delete the folder Developer-3.2.5 - it shouldn't effect your workflow in any way UNLESS you want to add an older SDK at a later date.
If you are interested in seeing more discussion about it, there is also an Apple Support Community thread that essentially says the same thing - that you don't need the folders.
It should be safe to delete, if for no other reason than if something does get messed up, you can just reinstall Xcode 4.