I can answer you 3) in the meanwhile until booxtor answers the rest, because I think this is important:
Onyx (the producer/manufacturer of the boox m92) definitely DOES NOT sell any black pearl edition.
onyx-boox.com (which sells the "black pearl edition") = artatach from poland
BUT!!!!: onyx-boox.com ≠ (not equal) onyx (the boox producer)
You can find the real company "onyx" under
http://onyx-international.com
You have to be very careful because this is very confusing. But fact is: artatech intentionally exploits this confusion and is responsible for it in the first place. They created the website extra to look like they were the official onyx company although they are just reseller. I'm not an economic lawyer but for me this seems illegal or at least unfair and I don't know if you want to support a business model that is built on confusing the consumer and strictly speaking betray the costumer.
The technical side makes the situation even worse due to artatech's attitude to lock "their" firmware, but that's another discussion.
Therefore booxtors firmware doesn't work with artatech devices (and that's definitely artatechs, not booxtors, fault, because booxtors firmware will work with any other boox m92 devices from any other reseller, except for the artatech ones), but please search in the mobileread forum and this thread for more information, it was already discussed often enough.