The only thing slightly different that I self host is WebODM. It's open drone mapping software. You can upload 10s or 100s of photos of an area and it can generate an orthomosaic, kind of like Google maps. It has a lot of other features too.
I don't really use it, I just play with it from time to time.
Ssh requires you to install the cloudflared client on your device that you are try to connect with.
Cloudflare Tunnels is really only food for http/s, all other protocols require a cloudflared client.
Just use docker-compose? Put multiple containers in one compose file. Create an internal network for them to communicate with.
Yes. It's mainly used for construction, people will map a large construction site once a week or so, so that executives can see the progress.