2 Questions about KO's inspired by NE/Balt game

[Raymond]

If this is the correct rule regarding kickoffs: 5. When a kickoff goes out of bounds between the goal lines without being touched by the receiving team, the ball belongs to the receivers 30 yards from the spot of the kick or at the out-of-bounds spot unless the ball went out-of-bounds the first time an onside kick was attempted. In this case, the kicking team is penalized five yards and the ball must be kicked again. ...

1) on the KO from the Baltimore's 35yd line had NE kicked OOB would the penalty choices still have been 30 yards from the spot of the kick or at the out-of-bounds spot?

2) How is an onside kick defined per the rulebook?