No attemps wil be made to log metadata (such as IP or user-agent).
The only data associated to an account are:
Connecting to the IRC service or logging into your account on the website will link your Username to your IP on volatile memory as your connection is being processed.
There's nothing that can be done to mitigate this on the server-side. Use a VPN or Tor if you're worried about it.
Law enforcement data requests will be complied with, be sensible.