I want there to be a way to not join vanished and be able to chat while vanished.

There is. It's called default.

If you join vanished, then you have given yourself the permission node for that. If you cannot chat while vanished, you have given yourself the permission node to do that. Don't grant yourself nodes without reading the documentation ;)

Sorry for bothering you D: but do you know of a way to take away one permission from a group? Like if you gave them vanishnopacket.*, could you do something like -vanishnopacket.command?

It depends on the permissions manager. You'd have to check the documentation for that. Don't worry about any bother, if I didn't like helping users I wouldn't bother having a way to ask for it :)

Thanks! I found a way in my permissions plugin, it really is just -vanish.joinvanished.