Woohoo! No panicking. :P
It's a -tiny- case of moutrot. Just barely beginning, and he's going to the vet tomorrow, after my math final, and after my own doctor's appointment. Will does in fact look him over, every day, while handling him. He's noticed the slightly swollen lip, and he regularly removes detritus from Mace(the uro)'s lip. He just didn't know how to notice the start of an infection.
But, it is all being handled ina timely and efficient fashion.

I just needed to know what substrate would be safe for this little guy, because I'm NOT putting him back on millet. Period.