The statement is correct, rsync by itself doesn't use ssh if you run it as an daemon and if you trigger rsync over ssh then it doesn't use daemon but instead starts rsync with UID of the ssh-user.

But, you can run rsyncd and bind it only to localhost and connect to that over ssh-tunnel. That way you can get benefits of rsync daemon and still have encrypted connection with ssh.

I think you don't need to specify that you want to use SSH. unless you give the location as starting with rsync://, or set to use the rsh protocol, it should use ssh by default.
just use user@targethost:path. The part before : is the same as what you use in SSH, and the part after it may be an absolute or a relative (to user home) path

So there is no way with Rsync (under ssh) to set settings (config file or other) that will apply to all clients !!??
So it's the client that configure rsync and the server !? there is no way around ?!

You basically want to use the daemon but under ssh. I looked into this before, and I think it is possible but the command for it is weird and confusing. Wish I remembered it, but just commenting to say that I vaguely remember there's a way (or maybe I'm hallucinating).

So... As long as you have ssh running open on the receiving server, you don't need the rsync daemon. Rsync client will ssh, then execute rsync recipient automatically.

The daemon is only for if you don't want to or cannot run ssh really.

Is there a specific reason you are looking at the daemon, or just unfamiliar?