Riley can produce a produce an amzing amount of dribble, I think that cat dribble is also 'wetter' than any other liquid lknown to man. I sometimes worry that he must be dehydrating himnself as it literally cascades from his mouth when he's purring/trying to cuddle me in bed - never had it after a play session though.
With regards him swiping at you, could his claws need trimming? My boys are mainly indoor so their claws can grow razor sharp and long quite quickly, he might have meant to do a playful tap but because his claws are long it hurt you. I find that I have to trim every two weeks or so to stop playful taps or 'paddling' hurting!