It's not really that privacy friendly, but I use zoho. You can send emails free from aliases with your own domain name so I have emails coming from nextcloud@mydomain pve@mydomain etc.
caleb
Not sure exactly sure how it all works. I've never needed to open ports for qbittorrent for downloading or seeding, I imagine it's the same principal. I 100% don't have any ports open and can see people actively downloading my music in slskd, confirmed even more by the thank you messages I receive for sharing.
Not sure on the first one. I've only had that happen on certain clients, but the fact that it happens in the web UI throws me for a loop. Have you dug into the logs when it happens? Looks like there is a debug option you can set in config. I'm assuming you don't use tailscale to connect while on LAN? When troubleshooting I usually try to eliminate things one at a time. Disconnect from tailscale to eliminate that possibility, connect via IP instead of hostname to eliminate reverse proxy from the situation and see if it improves, etc.
Regarding out and about, what is your upload speed? Are you using direct play or are you transcoding?
I built one with an esp32 and some tin foil and foam. link to guide. If you go this route read through this whole thread for improvements to the final product.