Is it team A's ball or is it turned over on downs if team A punts the ball team B returns it then fumbles and team A recovers it at the original line of scrimmage?

Answer 1

Not 100% on this but once team "B" receives a punted ball past the original line of scrimmage the ball has changed possesion. Team "B" then fumbles & team "A" recovers I would think team "A" would retain posession with a new set of downs.

AnswerIt is team A's ball on a new set of downs

Any time a change of possession occurs, a new set of downs is triggered. So Team A gets the ball back, 1st down. The same can occur if team A fumbles the ball, team B recovers it, advances it but fumbles it, then team A recovers it. Team A starts a new possession with 1st down.

Answer 2

As long as it doesn't go past the line of scrimmage Team A.

Answer 3

Team A cannot attempt a second forward pass. A team is allowed only one forward pass for each play from scrimmage. It is a 5 yard penalty if a team attempts a second forward pass.