I can't tell you what to do with YOUR kid, since I don't know your kid or you. I can tell you what I would do if it were my kid.
13 is too young to vape, smoke, drink or anything remotely close, period. I would have taken the vape gear away and punished him, like grounding him or whatever I thought would make my point. No video games, no phone, no computer. You know, the things they think they can't live without lol.
If his friends won't except him because of it, then GOOD! If that is the case he needs new freakin' friends. I am also assuming his friends are of similar ages, so I would contact his friends parents and see if they know what is going on. Sure you might not be popular for a while, but I never thought I was supposed to be my kids "buddy". Sometimes you have to make choices that they don't like. It is just a part of parenting. Just like your boss at work. If everyone likes them, they probably are not doing their job very well.
Acting up, missing school and threatening suicide because I took something away he isn't allowed to have would have back fired badly with me. This is just another reason NOT to let him do it in my eyes. I would have taken him to the school counselor, his family doctor and a psychiatrist. And maybe the truancy officer if he was skipping classes. If he wasn't joking he would get the help he needs. If he was joking or trying to manipulate me he would regret it.
There is also nothing in e juice that is that addictive, even if it did have nicotine in it. Nothing that would cause mood swings or acting out. There is also nothing in it that would make him "feel" happy if he had it. He is just .... hurt because mommy took his toy away. If he is threatening suicide because you took his binky (vape gear) away he needs help of some sort. Doesn't matter if he was joking, manipulating you or he was serious.
In my day I would have got smacked up side the head, grounded, and my mom would have smashed the mod with a hammer while I watched lol. I wouldn't suggest smacking your kid in the head, but the other too options seem pretty viable to me. Well actually I would probably use his vape gear in front of him just because I am an a hole like that.