Can a quarterback cross the neutral zone and retreat back behind the neutral zone and throw a legal forward pass?

Yes! The only restriction is that the passer must be in or behind the neutral zone, with both feet, when the ball is released. Rule 7-5-1

Agreed.

Yes, over and back is legal in NF football (where are you overandback?).

NCAA Rules
 

Isn't this illegal in college?

Peace

Canadian Ruling
 

Legal.

Legal. Just remember, there is no defensive pass interference after the first pass is complete but the restrictions for A are still in place.

Foul in college. Any forward pass thrown after the ball has crossed the NZ (in player possession mind you!), is illegal in the NCAA book.

What a bizarre rule. Let me ask 2 related questions then...

Lineman #59 receives a legal handoff, runs 5 yards past the LOS, returns back behind the LOS, and throws a pass. Illegal man downfield?

Lineman #59 receives a legal handoff, runs 5 yards past the LOS, pitches to QB #11, who immediately throws a pass. Illegal man downfield?

If the pass is illegal, there is no foul for ineligble receiver downfield. That becomes a foul only if the pass is legal.

And to stretch it a little bit further:

1&10 on A 20. A1 fumbles the ball on A19, and the ball rolls to the A 21 (crosses the NZ). The ball is muffed (by A or B) at the A 21, and the ball rolls back behind the NZ. A2 picks up the ball at A 19, and throws a forward pass.

Legal. The ball crossed the NZ, but was never in player possession beyond the NZ. Therefore legal.

A's QB can throw a completed pass for 20 yards and then the receiver, chuck it back to him, and the QB can throw it again for all I care. Another one of those WACKY NFHS rules. This is one of the rules (which are few) that I have great disgust for. It's not real football.

No Limit on passes
 

In NHFS rules there is no restriction on how many passes can be thrown during a scrimmage down, just so long the passer is behind the NZ.

Well how many times do you need to use this rule in football? I have never used it.

Dommer, you have several posts above yours saying that even if the ball is IN possession past the NZ, and it returns to behind the NZ, it can be thrown. Then you imply (twice) that it's not legal.

And no one answered my question. If the lineman passes the NZ, pitches it back behind the NZ, does he then also have to get back to the NZ before a pass can be thrown?