Big support delays are no longer a thing :) Please, however, remember that asking a moderator for help, will not guarantee that a ticket will be answered faster.

As for the missing game: I found no completed order on your account, just one attempt in 2020. If you are sure that you purchased the game on GOG, providing our support team with, for example, a transaction confirmation could be very useful.

No idea, this is a good question to ask within a ticket :)
Key resellers work in mysterious ways, which is why we do not recommend purchasing keys from unreliable sources. It's also possible that the key has been cancelled long ago, but you did not notice at first, because our games are DRM-free and being logged into the correct account to play them is not required. In other words, hard to tell without looking at the key itself.