Unabated to the QB is when a player comes offside without being touched by the OL (typically a wide edge rusher) and the refs blow the play dead immediately to protect the QB from taking a hard, unprotected hit. It's the same 5 yard penalty, it just stops the play then and there and denies the offense its free play.
Yes that's correct. If you fair catch a punt/kickoff, you can attempt a field goal from that spot with no rush or defense. But, it would have required a poor punt.