I think we should use some common sense here. If the clock has not started and the first touch results in a violation, I don't think the clock should have run. It's kinda like that "legal touch" language that ends a throw-ins.

Unless it's the end of the game and getting the time correct is paramount, I will probably ignore trifling timing errors.

Regarding the other issue, if a player catches the ball with a foot on the sideline, is that really a legal touch? Wouldn't the ball come back to the original throw-in spot just like if the ball never touched anyone inbounds before going out?