”变成“ vs “变成为” 有什么不同？
"变成为" is kind of redundant. It is the same as "变成".

Here the "stem" of verb is "变", while "成" and "为" are two "suffixes" that have similar meaning.

"改造" and "改造为" are totally different. "改造" means to change something. "改造为" means to change into (become) something.