i don't think this is a stupid question , actually it's a good question but the answer for both parts is the same i guess.

my thoughts :
prices will be in satoshis as 1 btc = 100 millon satoshis (100, 000, 000) so we have a lot of time until bitcoin prices could cause a problem.
or
people will turn to an alt coin for small payments as you thought.

there are no stupid questions mate, we are all noobs at something :D