On any inbounding play is it a violation if the inbounding player:



1. Steps ON (but not over) the boundary line without releasing the ball?


2. Steps ON (but not over) the boundary line then releases the ball?


3. On any inbounding play is it a violation if an offensive player receives the ball AFTER stepping on the boundary line?


3. On any inbounding play is it a violation if an offensive player receives the ball AFTER stepping over the boundary line?


4. On any inbounding play is it a violation if the defensive player steps ON (but not over) the boundary line without reaching through the plane?

The boundary line is OOB. It makes no difference if the line is 2"wide, 8"wide, or extends all the way to the wall (in which case the inbounder is always tepping on but not over" the line)

So, 1 and 2 are legal. Both number 3s are violations if the "offensive player" is other than the inbounder. 4 is a vioation for "reaching through the plan"

1. No
2. No
3. Depends on his location when he touches (or is touched by) the ball. If he has re-established inbound status (something touching inbounds and nothing touching OOB), then it's legal to touch the ball.
4. Kind of a trick question. If the defensive player steps on the OOB boundary, then he has broken the plane and committed a violation. So, although it's not possible to step "on (but not over) the boundary line", I think the answer to your question is yes. A defensive player who steps on the boundary line has committed a violation.

no, the the thrower is still OOB. Only touching the court inbounds is a violation by the thrower.

no. same as 1.
If the throw-in is a designated spot throw-in, no teammate of the thrower can be OOB once the throw-in starts. So this is a violation. If you don't call that one... If A2 is still touching the line when he receives the ball then he has committed an OOB violation. Team B's ball at that spot.
See previous #3. I'd be much more likely to call the first violation given there.

Warning for delay: breaking the plane with ANY part of the body.