I do really care to find an explanation about how a user profile (QS) is breacking forum rules (deserving an urgent ban), as you confirmed, and still active as always. Even it's confirmed that he own an army of alts, this is not a reason to not ban him, because no one leaves the forum for real after being banned, and investigations can be made for every suspicous account to be an alt of a banned user.
What i understand from your post, is that the forum will face big troubles if the administration ban QS. Is this really true?
I don't think it would be "big troubles" or if that is even a consideration for not deleting those posts and/or not banning him. Moderators have discretion in these decisions and that's generally a good thing, as it also works in favor of more reputable members if they occasionally step over the line.
Quicksy is a sleazebag so he has probably worked out a way to slide just under the moderators' tolerance threshold. He's not the only one. Take cryptohunter for example. Utter troll, derails every discussion with his rants. The price we pay for free speech is that assholes use it too.