I'm not sure it's possible for a BBS to have "cliques". At least, not like their real-life counterparts.
Wikipedia defines a clique as "an exclusive group of people who share interests, views, purposes, patterns of behavior, or ethnicity." Emphasis on the "exclusive."
But one of the most distinctive characteristics of an internet forum like this one is its very lack of exclusiveness.
Literally anyone can "join a conversation" in an internet forum, simply by posting in a thread. There's no way to stop them--not even by putting them on "ignore."
In real life, people stake out physical territories for themselves and their friends, from which others are excluded--tables in the cafeteria, or at the bar, for example. And in general, people respect each other's territories--unless they want to pick a fight, or engage in some other kind of battle for status.
If others do trespass on our territories, we either try to eject them ourselves, or ask others to eject them--the proprietor, or, in extreme cases, the police.
But an internet forum is a table that anyone can join. And if you don't like the company, the only way to escape it is to get up and leave--even if you were there first. And even then, there's nothing to prevent the people you dislike from just following you to your next table.
The closest thing I've ever seen to the clique-ishness of real life is a friends-only online game. And anyone who plays games online knows exactly why people play friends-only games: because the internet is full of assholes who like nothing better than to ruin other people's fun.
To have real cliques here at the TrekBBS, there would have to be some mechanism to allow friends-only discussion--that would allow the OP, for example, to regulate who gets to post in their thread, and who doesn't. Only that way would you be able to simulate the exclusiveness of real-life cliques.
Without such a feature, it seems to me that accusations of clique-ishness are just sour grapes. Nobody likes me, everybody hates me, I'm excluded, boo hoo hoo.
Well, guess what? There's no reason why anyone should like you, or include you. Other people don't owe you anything, and that includes their time--even the time it takes to read your posts at an internet forum, let alone reply to them.
If you want people to like you, or even reply to you, you have to give them a reason to do so. You have to offer them something, in exchange for their time. And if you've got nothing to offer, then expect nothing in return.