However, since the '?node=' notation is (a)ugly, and (b)could possibly change someday,

Regarding B): while I suppose there is a remote possibility of the node= notation changing (there is also a possibility that I will win the lottery on the same day I meet and marry a super model) I can assure you there is absolutely no possibility that the node_id=XXXX style of linking ceases to function as long as the site is running.

Point A) I can't help you with :-)