Thanks for your comments, guys. I will post an update soon before stopping this one when I'm abroad.
One thing: I think one reason for the Kings sucking that much was - I hate to say it - sliders. I really felt like being cheated by the CPU at times when guys like Calderon lit me up inside or David West couldn't hit any open shot etc. It felt like the CPU had some advantage, even though we had the same sliders.
I played around with the sliders lately and really found out some interesting stuff that helps my team being better, even though I don't use different slider sets for the CPU and me.
For example, I did not get many rebounds with Cousins/West despite having decent rebound rating. A reason for this was, that they both have a bad vertical, something which is way too important in the game for rebounding, while it isn't IRL.
Further neither the CPU nor me had enough TOs, which is bad for a team like my Kings, as I have the Fastbreak coaching option on 95 and like to run (who wouldn't with guys like Evans or now Williams)
I had two games with the new sliders, one was a clear loss, but it felt very very deserved, something that wasn't the case before often. The other one was a win, with me simply being the better team (it was against the Bobcats, who really stink it up in this D)
I was tired of loosing against bad teams like the craptors or the Warriors being lit up by Curry, Ellis, Calderon etc inside and blown away by guy hitting contested threes. Now it's looking better. This will affect this D for sure, but the D-Will trade did either, so don't blame the slider change for the Ws coming up more often