While I'm pro-pair programming I totally understand these issues. The way I normally go about it is put it out there that I like pair programming. And if other people in the team feels the same way, usually that just clicks.

I definitely think PP shouldn't be mandated at all. I think too that some of the issues you bring up are very important - especially about the notion that the soft spoken person will usually have their ideas rejected. A lot of developers act in very peculiar ways often because software development shops can be very toxic. Instead of addressing that toxicity, most places end up with a few head honchos. It really is bad for companies actually and can lead to many great budding engineers to leave or get out of the profession, sadly.