(I do this only very rarely, and even then I didn't aim for complete anonymity, just a buffer against knee-jerk reactions.)

Which I'm fine with.

Agh that would be so lame. Also clearly immoral.

Lame, yes. Possibly immoral, I don't have a good sense for how much you would care about undermining the Less Wrong karma system. People here tend to be too worried about the integrity of the karma system. It is much more robust than people realize because it is really just a stand-in approximation for actual reputation which is why actual cases of karmassination have been quickly remedied when the user was in good-standing. I'm more worried about the site overreacting to threats than any of the suggested threats so far.

Someone is either making it seem as if I am being obvious about it, in which case they are clever, or did not anticipate the consequences of choosing a name that rhymes with mine after I threatened to do that if I were banned, in which case they aren't clever and have a very strange way of thinking.

Either way it sounds reasonable to ban the account.

Someone is either making it seem as if I am being obvious about it, in which case they are clever, or did not anticipate the consequences of choosing a name that rhymes with mine after I threatened to do that if I were banned, in which case they aren't clever and have a very strange way of thinking. Given what I've seen of Thrill_Shoesome &c. I've found it suspiciously difficult to discern which hypothesis is more likely.

Incidentally, sockpuppets that by strong implication are impersonations of another user are at a whole different level of "BAN! BAN NOW!!!"