Sign Language is not that hard to learn.
There is not other real 'special care' for a deaf person, they tend to their own stuff, can cook, clean, laundry, feed themselves, turn themselves. Even enjoy music to a degree - as long as its something with a beat and you turn up the volume.
Your concern for communication is valid. Just think, his folks are hearing people, they had to learn sign language in order to communicate with their son. So they didn't start off signing at an early age, they learned it as adults.
Those other concerns are not really there - no special care required.
Your feelings are kinda valid and are most likely partly cause by the myth that anyone with a disability is unable to do stuff thus needs more attention. That only applied with people with physical limitations in specific areas - for instance don't expect a man with a cane to win the Boston Marathon (bombs don't help).
Understand he has adapted to his condition.
I take it he was born deaf or became deaf at a very early age. Typically folk that are deaf that early are very reluctant to talk because they just know that they sound like an idiot to everyone else and don't want people thinking they are an idiot.
So there will need to be trust and privacy for him to actually speak to you. Don't expect him to talk in public situations. At home, sure.
That communication thing is a two way street, say its a trade agreement, he talks to you verbally and you learn sign language.