If your safety is a concern (as he threatens suicide - it is) I would get him on recording. I would try to file an order of protection. You shouldn't have to live in fear. As far as the legal side... I understand you want to get it done quickly.. but there are ways that he can be served (even if he's homeless). If he doesn't show up to court.. it's his problem. I hope that helps. I have heard if they cannot find a person to serve they put a public notice in the paper (sewer service) and it's totally legal. Then when he doesn't show up.. everything will go your way
Hope that helps.