Thanks a lot for this detailed response and the reference to the resources! It helped a lot!

I can give an update on my progress.

I have a functioning matrix server with the mautrix bridge running on my pi now. For livekit I’ve followed your recommendation and set up a VPS for that as well as for routing traffic to my pi (due to my ISP’s policies it is a hassle to get inbound traffic working without a VPN).

The next step now is to get an Android Virtual Device configured and running for whatsapp to receive messages through the mautrix bridge (or get hands on another phone to run whatsapp on there). Having to resort to mautrix is unsatisfactory to me as I would prefer to completely get rid of whatsapp. I am trying to get people to switch to matrix but getting people to switch is a tough fight against the demons of indifference and convenience that so many people value over everything. I guess that is the price people have to pay for trying to live a more privacy conscious life. Until something switches in people’s minds using the bridge is unfortunately the best it gets for me.