John has the patience for most anyone after Sherlock... provided they aren't sociopaths. I think we're good there, though! Ryu looks like someone John could get on well with when John isn't being exasperated by Ryu and his obliviousness to things like the necessity of clothing.

As for the limp, John's free of that unless something takes a serious bad turn in the game. I am contemplating him continuing to suffer from nightmares, though. That's not something the show really explores after the first ep, but I imagine any veteran would still have them.