Answering your questions:
1 - Yes;
2 - (j);
3 - I think so, from what I could check all updates were successfully installed;
4 - I believe it is the original Microsoft driver and there is no update. Here's a note, my keyboard is a Razer DeathStalker, but I don't use Synapse, just the Microsoft driver;
5 - I didn't reinstall, it took me a while to realize that the problem was the anti virus;
6 - KSC Premium.
Thank you.