Correct. For me it was not totaly clear why you can either say "disc in" or "stalling" but it is correct that the player checking the disc doesn't necessarily have to mark so he has to have the option of just calling "disc in".
So any stallcount has to start with the word "stalling"
Yep. Initially I confused myself by wondering whether you only needed 'stalling' at the beginning of the stall count and it wouldn't apply when RE-starting a stall count that had been paused by a call. But actually the rule on restarting stall counts [9.6] does also demand the word 'stalling'. So I think we've covered everything on this one.