Questions about anonymity on lemmy.world servers - Lemmy.World

I’m trying to understand how safe it is to use an account on lemmy.world to post dissenting opinions regarding the U.S. government. I have three questions: 1) If a subpoena is issued for IP records for a user or their comments, will all historical IP data be available to provide? 2) Is there a time limit on how long IP records are kept? 3) When a user deletes their account on lemmy.world, are their comments and/or IP records also deleted? Asking for a friend…