The "clique" threads can seem overwhelming but you don't need to be able to go back and read all 10000 pages. Just go over, maybe read the posts from that day and say Hi and introduce yourself. If no one answers right away they may all be gone for a while. Stick around and see what happens.
I was new to one just a few weeks ago. But everyone took me in and I have made some great friends. If you don't understand some of the inside stuff PM someone and ask. You can usually figure out who the best person to ask is after a few days. I can't think of anyone that wouldn't be happy to explain. An "inside" joke is more fun if you share it.
Yes, there are hijackings. I don't read everything that goes on, but it seems that a lot of times they are by people that already know the OP, or on threads that are meant to be silly anyway.
To the OP and others that feel ignored

I am really sorry. This is a huge board and things do tend to get lost sometimes. Sometimes finding a few kindred spirits that you can hang out with is more fun than hoping that a few of the thousands here will reply to something. I hope you find this a more welcoming place in the future.