I can completely see your point, and on a literal reading of the law I don't think that shining the ball is legal - because by doing that you are altering the condition of the ball.
Hazarding a guess, the difference may be along the lines that when you're shining it you're basically preserving and maintaining it, whereas when you're gouging etc you're damaging it. But I realise this isn't a sustainable distinction - apart from anything else, picking the seam is closer to preserving the state of the ball than damaging it.
Yeah, that was my guess, but like you said, that should mean that picking the seam should be completely fine.
IMO, as long as you're not using any un-natural equipment (ie vaseline, bottle tops, razor blades, boot studs etc) you should be allowed to do whatever the **** you want with the ball.
edit: you're wrong wrt shining the ball:
3. The match ball - changing its condition
(a) Any fielder may
(i) polish the ball provided that no artificial substance is used and that such polishing wastes no time.
(ii) remove mud from the ball under the supervision of the umpire.
(iii) dry a wet ball on a towel.
(b) It is unfair for anyone to rub the ball on the ground for any reason, interfere with any of the seams or the surface of the ball, use any implement, or take any other action whatsoever which is likely to alter the condition of the ball, except as permitted in (a) above.
Source:
Law 42 (Fair and unfair play) - Laws - Laws of Cricket - Laws & Spirit - Lord's
Although b) seems to somewhat contradict a)
IMO there's absolutely no reason to permit a) and outlaw b) They're both pretty much the same thing.
edit 2: You'll often see spinners rubbing their hands on the wicket, presumably to dry their hands and aid their grip.
I really don't see why there's a distinction between drying a wet ball on a towel, and rubbing the ball on the ground. There's a pretty reasonable argument that they'll achieve the same thing.
Anyway, I'm starting a new thread for this discussion, don't want to clutter up the tour thread any more.