I've been waiting until after Christmas day to make this post, but some of our communities recently have had a lot of noise and upset over someone that uses neopronouns that most people are unfamiliar with.
So I want to make this clear. A persons pronouns are to be respected. This is true when the user is using neopronouns that you're unfamiliar with. It's true even if you think someone is trolling. Pronouns are not rewards for good behaviour. They aren't only to be respected when you like the person you're interacting with, or if their pronouns "make sense" to you. Trolls, spammers, twitter users, it doesn't matter who they are, your options are to respect their pronouns, or to not engage with them.
I really want to re-iterate the importance of this. Gender diverse folk are undermined, invalidated and questioned at every step of our lives. As a community, we need to be working to undo that, not creating more of it, and that means there is no space for treating pronouns (including neopronouns) as a reward for good behaviour.
This isn't a free reign for trolls and spammers. The rules still apply. Trolling, spamming, etc will continue to be dealt with, but it's not an excuse to act as if respecting someones pronouns is optional.
You sound like you've got the right idea and a good handle on things. Neopronouns are generally a very case-by-case thing and not at all common, people who use them generally will (politely and without fuss) let you know, and many neopronoun-users (not all but many) also accept they/them. It's not a thing that comes up a lot, and personally I think people tend to give the concept too much mental bandwidth. The important thing is to be respectful of each individual, if you're not actively being a dickhead you probably don't have too much to worry about on that front.