If you're wondering why comments of yours are being moderated, usually the answer lies in closer, objective interpretation of the comments or retorts you're referring to.
The staff here moderates the forum, but we will very rarely edit or delete posts. We don't have set rules here, I think everyone is pretty laid back about things. However if we feel a post is out-of-line we, of course, reserve the right to remove it. If everyone is being civil and mature, there should be no reason to remove anything. Thanks.
I have no idea of the context, so I honestly can't say if you're being treated unfairly or not.
I personally haven't seen much evidence of moderation of any kind on this forum. That's not to say there is none of course, but given some of the things that have been said without any action being taken, it's difficult to believe there is any heavy-handed moderation going on here.
I've seen my fair share of forums where the moderation is... incredibly strict, to the point of stupidity. That does not mean however, that it should be OK to just say anything whatsoever without consequence.
But, as I have no idea what you've said that's been deleted or modified, who am I to judge if you're being treated fairly or not?