"I really do not like bananas," was accepted. In English, "I don't really like..." and, "I really don't like..." are subtly but significantly different. (The first indicates mild dislike, while the second indicates strong dislike.) Does «Я не дуже люблю...» translate to both?
You are right!
Я дуже не люблю банани -> I really don't like bananas
Я не дуже люблю банани -> I don't really like bananas
Right now it's corrected :)
As far as I understood, "I don't (very) much like bananas" is grammatical. It's accepted, but sounds very unnatural and obsolete. The best would be "I don't really like ..." or "I don't like ... (very) much".
Yours is ungrammatical.
Disclaimer: not a native speaker