ha ha, withdrawing the hand is common among coptic priests too.
we don't get too upset about it, the usual coptic response to the withdrawal of the hand is for us to kiss our own hand that has touched the priest's hand. i suppose that would look weird if u were not used to it.
i think some priests just get freaked out by all the hand kissing, and i suppose it takes all sorts of people to lead the people. i think it's more complex than a humility thing.
as for wiping the mouth, we don't do this. we don't like to get any of the Holy Blood on any cloth. (we then have to wash it in plain water and then the priest drinks it or we can burn it).
with little kids, their mum / dad licks their lips for them if there is any leftover Blood. i didn't see any old and wobbly people spilling the Holy Communion, so i don't know what happens in that case.
with the chalice, it gets 'washed' out several times with water, that is then drank by the priest and any subdeacons serving at the altar.
the paten (for the Holy Body) gets washed out too, and the water drank similarly.
then everything gets wiped with clean cloths and put away.
we drink water immediately after communing, and then at the end of the service get the antidoran ('baraka') so any dribbles of anything holy get removed that way.
interesting how we all have different customs and nice that we all treat the holy things with the same respect.