It is an option, but not a particularly good one seeing as it’s run by amazon. I personally use Signal just because it’s popular, but Wire seems equally good, and I’m glad they exist to provide competition.

The server is physically connected to my laptop with only a switch in between. However, my Qubesos config has two routers (one of which is a firewall) between the hardware and what I’m actually working on. I checked with curl, and I have access to ports 2049 and 111, as well as the webui on 443.