"parking" jumpers on motherboard..

Unsure what you are asking, but if you mean can you place unneeded jumpers on "extra" motherboard pins - that is not a good idea. Put them in a small bag and keep them with your motherboard parts.

Well, as long as the unneeded jumpers are only on one pin, it won't make a difference. But if they were on two pins, it could cause problems, including short-circuits.

yes 1 pin, i'm sick of losing jumpers.

As long as it is only one pin, then it can't be a problem or make a difference. It could be annoying for anyone who doesn't know what has been done, though.