Re stats:
Personally, I found that focusing more on my winning percentage - ie, doing whatever it took to help the team win, regardless of what it meant for my stat line - actually helped me get better at the game, to the point where my individual stats are now rising up to the level of my win percentage.
My win percentage is 75% with 250 matches played, and that's with a combination of playing with a consistent group of friends (always a big help) as well as individually in the CTF, HardPoint and Attrition pots.
My K/D was a depressing 0.9 for the first week, but I basically put a conscious effort into putting it out of sight and out of mind while I focused on learning the maps, trying out all the weapons and abilities to find out what playstyle I was best at, and what equipment facilitated that playstyle best, and focusing on objectives or running support behind/beside other players, and basically learning through osmosis and observation.
Now my K/D has jumped to 1.5 and it's going up fast because my last-10-games K/D has been 6.0+ (with frequent peaks of 14.0, 16.0 even 20.0) for the last like, 40-50 games or so.