games done quick is on

matrix should cover everything you need with the added bonus that you can chat with people from other instances

you could try mailu. that should be simple and Provide you with everything You need

use haproxy instead of Port forwards, that should work just fine and works really well on opnsense

fairphone 5 is out :-) it is getting upgrades until the 2030s. and it is so easily repairable that it is realistic to use it for a long time