

Yeah I see no reasons why these two wouldn’t work. You could get an FXO to to go from that to VoIP, but obviously you’re losing encryption (I know, srtp and zrtp are thing but still) unbeknownst to your interlocutor which isn’t a very nice thing to do.
No, a dock isnt a computer. It doesn’t have ram, doesn’t have a CPU in the sense of a general computation device. While it might have an MCU and with a lot of reverse engineering I don’t doubt you could run Doom on it, it isn’t a computer.