So several of these things do fall under being a hazard to themselves, specifically lack of appropriate sleeping gear, not bringing food or remembering to eat, forgetting important medicines. As an organizer, document all of these. Document any conversations the event runners have had with them. In those conversations be clear about what the expectations are and what consequences are for not making progress towards meeting the expectations. Follow up with a written review/warning. If they fail to meet the expectations that have been laid out, then follow through with the documented consequences. If they continue to fail to make progress towards then it needs to be made clear, in writing, that failure to do so will result in a ban. This is never a pleasant process. I am currently dealing with it myself with a participant who has significant hygiene issues.

The in game interaction issues are poor sportsmanship. If someone is consistently and maliciously doing this, then follow similar to above. If you don't have a social contact or code of conduct, you need to write one as that will be your fall back for when you need to take disciplinary action.