I agree with the other guy. It isn't about how old you think the protagonist is, it's about how old he can be. You'll be able to decide how old your character is and make the appropriate facial changes to match this, in my opinion. So to say that the protagonist is in their 20s and 30s is completely silly in my opinion.

I mean, if we wanted, our PC could be 60 years old and have a 20 year old wife.

This thread is called "what we know." I suggest we stick to facts and remove conjectures from the list.

We 'know' very little, beyond that you can choose your gender, you are married, and have a child, and are supposedly the 'only' survivor of vault 111. Wonder how literally they are going to play that.....