I've heard your name come up on multiple counts, LCass, and not in a positive light. Further more, I am 90%, and by this I mean that I am certain that your name came up before the whole welderbomb attempt (and note, contrary to what you told us, that device was not inert), meaning, you had to have spent some time here prior to pulling that stunt.
Secondly, just about the only way I would see your ban reduced is with a supplimentary antag and sec ban in place.
Alright, let's look at it this way. Our issue: your conduct. Consistently aggressive, treading on our rules, and so forth.
Your issue: being banned from our server due to what I noted on the line above this one.
How do we solve this? And no, a simple "I promise to act better" won't punch through, as I've had too many people make me a promise like that and then proceed to take horrible liberties with it. And as much as I enjoy dealing with them, it's a case where pre-emption is better.