Honestly I want a Linux phone, but the scene needs to mature a bit. I’d also like a physical keyboard, so I’m even more limited in my options. LilyGo just released something I’d try, but it sold out almost instantly. Good call on the signal transfer, though I wish better platforms were catching on. Having to use a phone number to sign up kind of defeats the purpose in my opinion. Graphene and Postmark are on my short list of things to try if I end up on an android device.
To be totally honest I didn’t read your entire post, but just from your intro I think we are in similar situations. ISP router, low costs, using only the hardware you have around. I’ve solved a lot of stuff with Tailscale. None of my services are public facing and instead I connect to them over Tailscale (could be replaced with wireguard).
The wall I’m hitting you or maybe others could help with, is accessing my services from sub domains of a single Tailscale address rather than having to type port numbers for everything. I know this involves a reverse proxy and DNS (I use PiHole for that), but I’m stuck trying to configure the two in a way that actually works. Once I finally ditch iOS for good I’ll probably just sync a hosts file between all my devices using Syncthing to help streamline the DNS situation.
I use Unix Pass connected over Tailscale to a git server I host myself. The interface options for various devices are a bit clunky, but it basically “just works” outside of that.
Edit: I used to use KeePass and syncthing, which I think is probably the best (balance of simple and effective) combo for most users.