Telemetry is in Server -> General -> Allow Anonymous Usage Collection. When you opt-out, it also send a final message to the server that you’ve opted out. The the telemetry itself looks reasonable, I don’t mind sending it. It’s really just the dark pattern of opt-out vs of opt-in that bothers me.

The donate button is the heart in the bottom left menu (not visible in the settings). It’s unobtrusive. I wouldn’t bother to remove it, except the tooltip says that I have to pay to remove it - now it has to go. Asking for donations is fine, but asking for money to remove a button is disgusting.