There was a briefly a previous MiniCoin (just as there was briefly a previous ByteCoin), but it's gone and never coming back.
See the thing is, we purposely avoided choosing any name which had already been used by another coin. I'm sure that even if MiniCoin is totally dead, there are still many remnants of it on the internet which will cause confusion for people. It took us a very long time to find a good name which hadn't already been used, and the domain was still available. I also really like the logo we have, which I paid to have made. At this point it would be a total pain to change the name, but if you want to call it MiniCoin as a secondary name and redirect one or more of those domains to cryptonite.info I wouldn't be against it. Personally I just don't think changing the name would really benefit us very much, I think there are far more important things to focus on, and if the name is good enough now I see no reason to mess with it.
"Cryptonite" is already being confused with not just another coin, but with an entire family of very successful other coins AND that family's proof-of-work.
I'm not discounting the time/effort you put into the name, but am asking you to reevaluate the outcome of that process in light of the current situation.
Minicoin was a minor blip, it came and went without notice, signifying nothing. It's a great name for this project, and just sitting there waiting to be used.
"Minicoin' only appears in google 11,900 times. "Cryptonight" appears 33,800 times. "CryptoNote" appears 55,300 times. "CryptoKnight" appears 8,900 times.
I regret to report that your attempt to avoid a naming collision failed. That's just a fact, sorry. Pronunciation matters just as much as spelling, perhaps more.
MiniCoin was barely used in the past, and not being used currently. Based on your own criteria for originality and distinctiveness, MiniCoin is a better choice (IE does less harm) than Cryptonite, as it results in an order of magnitude less ambiguity.
We can easily ask our (handful of) exchanges to change the ticker to XMC, and make a new /r/XMC subreddit until we can acquire the full .com, etc. domains. It should be timed to coincide with the rest of the re-branding. It's not that hard; it's been done before.
Don't let the search for a perfect (totally virgin, free .com) name be the enemy of a name like MiniCoin that's very much good enough.
I think you are setting the bar higher than is needed. I've already registered the minico.in, minicoin.io, and minicoin.info domains we'd need for a switch.
If you have to veto MiniCoin reuse, let's go with MiniChain. I am happy to donate use of my minicha.in and minichain.io domains as well.
I'm not saying a name change is hassle-free. I am saying it is worth the hassles, and we are still very much in the earliest days of the coin.
Please do not doom us to an eternity of
When I tell people about this coin, I have to use the qualifier 'with a c-, not like in superman, and also with an -ite, not night, like, you know, the dark time after the sun goes down' and they say, 'oh it's like bytecoin or monero!' and I say 'no it's an all new POW called M7' and they say 'then why's it named after their POW?' and I say again 'no, it's spelled with an -ite' and they say 'oh like superman!!' and then I give up and change the subject.
I like MiniCoin because 1) it's an apt shorthand descriptor of the underlying mini-blockchain feature, and 2) it's a cute pun on ManyCoin, which is appropriate because there will be so many Minicoins.

Again, it reflects positively on a coin when the devs graciously accept community/userbase pushback. We have an opportunity to demonstrate how well we work together. Branding drama is annoying; we all want get back to work on building out the MBC platform. The sooner we resolve the unfortunate naming collision the better.
MiniCoin *MIGHT* be, in the worst case, confused with an obscure, short-lived, abandoned coin that went nowhere.
Cryptonite *IS* being confused with Cryptonote (a shady effort of uncertain provenance), a Proof-of-work, Superman's weakness, a bike lock, and an Android encryption product. Not to mention CryptoKnight, an obscure, short-lived, abandoned coin that went nowhere.

We can get another logo (or simply change the 'C' in the current one to an 'M'); we cannot get a second chance to make a good first impression on new users.