Regarding 1): The "games joined" stats now also tracks unranked games, which it did not before. That's why that count went up for you. It has to track unranked games as well to match up with the new "scenario joined" statistics, where we cannot distinguish between ranked and unranked.
1. Good guess, but I've never played an unranked game. Ever. The only possible explanation I have for this is that the system is now picking up 3 or 4 "country selection" games that I started to join, but then saw the bad choices of remaining available countries, and decided not to join. As I am sure you know, if you don't select a country within 90 minutes to 2 hours, the system kicks you out of the game.
Regarding 2): Sadly this is true and for now we cannot retroactively award those map wins. The stat that users won a game was tracked before the stat of the victory of those maps, that's why it is possible that the system knows about one but not the other. Our stats system will soon be revised once more, there might be a slim chance that this info can be recovered, but I would not count on it.