Squeaking before he pees= bad. Might mean stones= bad. Vet visit imminent.
Also might be impaction=worse.
As for not running around and making a fool of himself, he's probably scared of the open space. Guinea pigs are near the bottom of the food chain, get eaten by many. Instinct yells run for cover at any foreign movement. Try putting/making hideys out of stuff and placing it randomly about the room, pigs enjoy exploring new areas just put enough space between the objects that he can't get squished between, also that there aren't any wires within reach.
Guinea pigs are naturally more active during dawn and dusk. Don't ask me why. This might be a reason he doesn't want to play at noon. Also, they are active for about 30 mins if they feel like exercising. If you have a nice big cage, he probably runs laps around it while you're out of the room. If in a small cage, they need much more time out of the cage.
Guinea Pigs Social Life is pretty informative.