@Shotgunshell, I agree with Mayana. the perspective of the forum's internal workings there is no issue with deleting posts, but it may well cause confusion elsewhere with the flow of conversations, or indeed with topics generally, since even if people have not responded they might well have taken note of what you said.
Odds are anything and everything you have written on the forum has already been read by people anyway, ---- heck that is what a forum is for, so deleting won't much in changing what you've written.
Most people say something they regret, or have written posts in a bad mood (I certainly have), but the answer isn't to try and seep things under the rug with the delete option, the answer is just to resolve to be a better person in the future, contribute to discussions and interact with others on the forum in a positive way if you can.
So, delete posts if you really want to, but I'd personally just letting the past lie and working on the future instead.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)