OP: I know some of the incidents you are referring to in the Ebay subforum. Here are some thoughts that might help clear it up for you a little bit.
1. The Ebay subforum can be intense. People come there when they've been scammed or are dealing with difficult and frustrating buying/selling situations. Emotions run high and many who have been there for a bit have seen it all and tend to be more on edge. Additionally, scammers have come to test their scams, duping many into helping them perfect those scams, and then use that info to scam fellow tPFers. People are thus on guard as well and perhaps impatient.
I'm not condoning any behavior; I am just trying to give the subforum some context that might help you understand the dynamic. It's a very serious place and few go into that part of it for fun (although fun threads do pop up there occasionally).
2. Subforum etiquette rules aren't necessarily intuitive and that can make it easy for a new members to stumble. Trust me, we've all had to learn this too (and me in particular many many times, believe me). For one, we're not allowed to post two separate threads for the same issue. If the circumstances have changed, we update our existing thread. If we want more advice, we continue asking in our original thread. Because not only does starting a new one make it look like we don't appreciate the advice offered previously (even though it's not our intention), it also clogs the first page and other people's issues get pushed down and ignored. For that same reason, we're expected to do a "search" before posting a new thread to see if this has already been answered.
Nonetheless, even when we trip up, our fellow members should politely explain this. And I believe most of them usually do.
Little Rock is the main mod there and if there is a problem hit the report button or PM Little Rock and she will take immediate action. She's very good and she's extremely fair.
I hope you decide to stay. There are good people here. And for those who are rude to you, please know you can ignore or report. The mods here are very fair minded.