Kdenlive is one of the best video editors I have ever seen and I would use it and the industry would adopt it if these tools are added.

-Color Correction
-Splice in
-Overwrite
-Rolling Edit
-Stereo audio editing

These are the final things that I believe are required. I know you are trying to make it as user friendly as possible but maybe in settings you could change the tool palette in the bottom right. I am sure people will disagree with me so if you do post what the most important features for you would be.
Keep up the amazing work!

Color Correction is already provided in Kdenlive from svn via frei0r plugins.
Although it would be better if your were able to directly edit the curves.

yeah curves would be great or the circles. I don't know how else to describe them. And possibly have a separate window for it and keep it separate from effects. The current color correction effects are ok but need a lot of improvement such as mids whits and blacks sliders. Auto Contrast and Auto color may also be quite nice.
Cheers