It’s a good app, but if I log in to it will it send my data to damus client without connecting to more relays?
Discussion
Nah it won't bork your relay list or send any data to Damus. At least it hasn't for me.
I’m running one relay atm
Oh I see what you mean. You'll just need to add that relay to the Nostur settings. I also use their relay, see screenshot.