The data send to other servers via Federation is not critical private information like an IP address, however you are right that due to the way Lemmy loads images from other instances, IP addresses are currently leaked to other servers. But I hope that will be improved with a better image proxy in the next version (Lemmy 0.19.x in combination with Pictrs 0.5.x).
It’s nice that you promise to not abuse this and I trust that you are not lying about it, but this is a general problem and I don’t think services like this should be used as your instance’s users are usually not aware of the implications.