Gheebat and Mocking

Is backbiting shirk?

Q: Does backbiting mean its shirk and after judgement we cannot go to paradise even after Nabi (sallallahu alaihi wasallam)'s intercession?

If I backbited and do not go to the person because of feeling shy, how can I tell this person? Can we do tauba so that Allah knows that we tried our best not to backbite? Can this be forgiven?.

Does making fun of another language result in making fun of the signs of Allah

Q: "And among the signs of His power is the creation of the heavens and the earth and diverse language and skin color. Surely, with that situation actually there are signs for people who know" (Ar-Rum:22)

According to an intrepretation. If I make fun of someone speaking in other language which seems funny, is it as if I made fun of a language (Allah's sign) and thereby kufr?