Hello there! Welcome back!
I'm going to say: don't worry about your opinon not mattering here. I believe in PC, a respectable open-minded member is open to all opinons, and judge based around that. I typed this before: having an open mind consists of having patience and acceptance of all views no matter how dissimilar to your own that they may be. Each person's opinions are their own and like it or not, having an open mind precludes a person from the chance of trying to hold another person back because their views are different. Well, its what I think...
I too am sorry for you're past experiences with forums; I don't really know and I can't say what its like in the forums you visited in, I can tell you right now, that I don't think your a jerk of any kind. I believe your a kind, member who just like the rest of us, just wants to have fun. And I do hope that things will go better this time around~
Now, I did used to play pokemon copetitvely in my time, but eh, I guess it got kind of boring, and redundant; I found that people laughed at you for using "tiers" that are beneth the casuall "OU" tiers, so, nowadays, I just play pokemon for fun. MAYBE I'll come back around when Pokemon Black / White comes out, but, not likely.
But yeah! Welcome back~!