Would repentance of a murtad fitri (One who is born to islam but leaves as an adult) be accepted by allah?

If yes, would he need to compensate for the missed prayers and ramadan fastings?

What about Kaffarah (Recompense) for ramadan during that period?

Inshallah Allah will accept repentance. He has to do qaza of missed prayers and fast.
There is no kaffara for that