My Questions on Otaku.com

I have many questions, because I have been having problems since Ive made an account. If anyone can answer these itd be a GREAT help:)

1.) Whats a Guest poster?
2.) When Im chatting I only get to say "hi" then when I try it again and press 'enter' it wont send. Id have to exit the room then enter again. It sucks because its so bothersome!
3.) I cant figure out how to answer my signatures, comments, and how do I signature or comment on someone elses. Im not sure if its that I dont know how or if it wont let me. Because I tried pressing 'reply' and it literally does NOTHING.

So far thats all my problems. Im literally at the point where Im gonna deactivate this and make another. If it still wont work then im just gonna get off permanently. I find this website enjoyable, but I hate how I feel limited.
Well if you guys can help I will really appreciate it, suggestions are grateful as well.:)