Hey, I am a DD main although playing a lot of cruisers and BBs now, I am generally unicum. (my stats) I am currently grinding the KM DDs and am at the Maass.
Frankly so far the KM DDs are terrible ships. You won't get good cap contesting until T8 apparently, until then your spotting disadvantage is too great entering caps. You would best serve your team spotting and waiting until the DD in cap has capped and left unless you can use islands to your advantage to stay unspotted until you can ambush.
If you are able to do this two things will happen:
1. You will have support and that DD will use smoke. DON'T FIRE YOUR GUNS BEFORE THIS HAPPENS. You can then get close to the DD with your hydro active and spot them in their smoke, now is when you use yours and happy times ensue.
2. They are a smart player and know your guns suck, they will kite you while their team hammers you, use your smoke and mutter about how your team isn't close enough to support you.

You must remember that the longer you live in a game the more useful you will be to your team. Dying trying to contest cap at the start is a waste of your potential. Almost all your damage as a DD will be in the mid to late game.

You need CE, really you need it.

Regarding CVs, the best thing you can do is smoke or run while wiggling your shiny ass. Don't wiggle back and forth, you need to vary the amount of time in your turns so as not to be in a straight path or people like me will just shoot ahead of you and get good hits.