I see quite a lot of MH cases when I work on an ambulance, and there are two things that really remain consistent. One is that it doesn't matter how much you help someone if they don't want to help themselves. The other is that there are some people who just can't be helped, even if they want it. They will assault people and they will cause serious harm to others without realising it.
I don't know if ROL falls in either of these categories, but you have to see that these sorts of threats are not normal behaviour of an adult and are not fixed with kindness and respect. If they are fixable, it is done by proper medical therapies and medication. Giving people who are mentally unwell, especially incorrectly medicated schizophrenics (they have prescribed medication but they would not be allowed to attend whilst taking the medication) the space to do stuff like shoot themselves in the head means they WILL follow through with the threats. An online community of gamers has 0% chance of helping this person, and will ACTIVELY BE PUTTING THEMSELVES IN DANGER BY TRYING.
Having interacted with people like this DURING their mental health crisis, I would personally NOT go to any event they had a chance to show up to and I would suggest to remove them from the greater community if the organisers of these events wanted them to remain safe. It is unsafe for them and unsafe for the rest of the community to have them at such a place without either a trained full time chaperone or having them in handcuffs, which is no way to be treated.
To say a point about being nice in the community, I'm going to take a different stance. You don't have to be nice or be friends with people but the scene isn't very big, so you have to be able to work with people if you want to keep playing. From my perspective, I don't really want to interact with someone who is that mentally unwell (severe schizophrenic having multiple crises), or someone who is just a cunt. I would rather not play than play with many people in this community, and it's a large reason I don't play pugs anymore (I used to play a lot of pugs).