To play off what others are saying i think a mini pc and a stand alone nas may be the better route for you. It may seem counter intuitive to break it out into two devices but doing so will allow room for growth. If you buy a creeper bare bones mini pc and put more of your budget towards a nas and storage you could expand the mini pc without messing with your nas. You could keep the pi in the mix for a backup if your main pc is down or offload some services to it to balance performance.
zerodawn
Underrated explanation, you held it finally click for me. I consider myself a fairly educated person but just couldn't wrap my head around what made it so special. Correct me if i'm wrong but my understanding is the server uses the public key to encrypt a challenge code that can only be decrypted by your private key. You get an on device prompt to approve the process and the rest is done under the hood.
To go further on this, is the public/private key a mathematical relationship? What ties the two together to make them useful as a pair?
One is a hopeful future the other is a mythical past. I lean towards trek because i want to believe a version of that future is possible.
AudioBookShelf is a beautiful podcast option. OP would have to fully migrate into it but once done it'll let you listen to an episode on pc, pause, then resume from the same spot on mobile. It'll auto grab episode as they come out and store them on your system for streaming or local access. The android app is pretty good and i know webapp works well on ios
That goes hand in hand with a level of trust with some companies/people and everyone has different threat tolerances. It also highlights the mindset that you have no idea what the person on the other end of the message is doing with it. End to end encryption helps keep in line eavesdropping down but if the recipient of the message has a compromised device or are screenshoting everything and posting it on facebook it's out of your control.
As someone else said, selfhosting is the only real way to overcome this problem. When it's all on your hardware it matters a lot less if the messaged at are decrypted server side or not. Everyone has a different threat level and at some point you have to put trust in some companies but if beeper makes you uncomfortable then buy a cheap second hand mini pc and learn to self host the service.
I'm never a fan of virtualizing network related items for the sake of redundancy, if your server goes down the rest of your network can keep doing it's thing. That being said, with the hardware you have on your hands i don't see any solid atonemen argument for bringing in more hardware.
Proxmox is a great base for you to really ramp things up and i'd recommend looking into pfsense as a routing/firewall solution. There's a bunch of great youtube videos that can talk you through setting it up and using it as your vpn point, adblocking, reverse proxy, and so much more.
I'm no expert but my understanding is all drinking cans are lined with plastic to withstand erosion.
https://www.ehow.com/facts_7390219_metal-cans-lined-plastic-coating_.html
https://github.com/florisboard/florisboard/discussions/2314#discussion-5761611
According to this it's still planned, though time will tell.