I'm not for K/D ratio per se, but as an overall factor in scoring it has it's place I suppose.
For the RO take on TDM, which is coming whether we want it or not

, K/D ratio is pretty much the only way to score the game. That's because it's a shallow, simple game type. Fun, but not much else there.
For Territory, I think the scoreboard should show your overall score, and then caps...and maybe even a bonus for being in the winning cap at the end.
For Countdown, I'd have the same one as Territory...but with a column for Deaths. Not for your kills,,,but just your deaths. And again your overall score and your caps.
Campaign I think should look like Territory for the most part. Same game, just longer. I'm guessing of course.
Overall Score / Caps / Caps FTW / Kills / Deaths would be cool to have as persistent stats. Let Steam Achievements handle the rest...I'd be fine with just that.
But looking at the new gameplay video, it looks like TWI have really put A LOT more thought into their scoreboard and how scoring relates to the progress of the player. So...I think we should stop worrying about any of it.
If you're all REALLY honest with yourselves....there's not ONE thing in that new HD footage from Yoshi that TRULY makes you cringe at the thought of buying this game and playing it to death. All I saw in those 14-15 minutes was enough to further convince me that the wait is worth it...and the wait is coming to an end.