The manual wasn’t enough to answer those specific questions, hence me coming here to ask. I found it to be pretty vague on the matter. It defines herding, carrying, etc., but doesn’t really outline what I’m asking.
There are a number of other threads that address this. Please also read the rules carefully to establish your own opinions.
But, to address your questions, in my opinion (which counts for nothing at an event) based on my reading of the rules, team updates, and Q&A:
A bump would not be “herding” (and hence not possession) unless it was really obvious that you were propelling the ball to your partner. Some sustained or repeated contact with the ball would be necessary to establish this.
If the ball moves as a result of a mechanism that is in motion relative to your robot (a puncher, wheel, belt, etc) then you have established possession.
There is no requirement that the ball not touch the floor. You can “pass” the ball along the ground.
How the ball goes between robots doesn’t matter at all. Review the section on scoring. All you need to know is what counts as POSSESSION and what doesn’t.