Another option: a mute wizard with
ghost sound. I think it's a little unclear if you can produce words without speaking them yourself, but at the very least you can use it for entertaining accompaniment to your pantomime.
This is how my swordmage/wizard communicates when he has to speak more than normal.
He has a bad stutter which he is highly embarrassed about and so avoids talking unless it is necessary. The stutter stems from a traumatic event in his past. Funnily enough when he speaks of revenging himself against the author of said traumatic event the stutter completely disappears (not that he notices that).
The stutter also lessens when he is using magic. So he has learnt that by flicking a magical coin into the air repeatedly (predigistation) he can lessen the stutter considerably.
But, sometimes you need to get a lot of information across without wrestling with words, so he uses Ghost Sound. I have him drop his head when this happens. I think a bluff roll would be necessary to try and make it appear as though he were actually talking. Also the quality of the voice, though his, is just off. There is something haunting, wierd and unpleasant about hearing his voice this way. And it is something the character dislikes to do in extremis.
This is how I try and express my characters Charisma of 8. He's a smart guy (Int 18) with lots of good ideas. He's even fairly sensitive and wise (Wis 13). But he really struggles to get those ideas across. And when he does manage it they way they are communicated are none too convincing.
I think it is important for you to decide as a player how much you want to be involved in the RP side of the game. A mute PC with limited or no ways to comunicate will mean a certain self-margianlisationin those areas. If you do want to participate in those areas, despite the limited ability to communicate, then you need to figure out how you are going to do that as a player first, and then translate it into how your PC manages that.
I wanted my PCs communication to be limited to reflect a weakness in his mechanical stats. But as a player I want to be involved in everything going on in the game. What I wrote above was my solution to that.
