Do you think you'd feel as connected to your family if you could only communicate with them by writing, while you can communicate with everyone else by talking?

Yes, there would be a level of isolation. It needn't be extreme, but I can't imagine there would be none

It's really no different from immigrant families where the parents don't speak English, but the children speak both languages.

I've known plenty of people and families like that, it was never an issue.

I've known plenty of people like that where is was an issue. The parents can't rely on neighbors because they can't communicate. Don't have as many friends. Have trouble at local stores, doctors, agencies, etc...

>Do you think you'd feel as connected to your family if you could only communicate with them by writing, while you can communicate with everyone else by talking?

Maybe more connected? If you are using a language that few others know, seems like it would enhance the "specialness"