The Projects plugin in Kate just gained a context menu for the tree view that shows several git tools, if available:
Clicking will open the corresponding application in the correct working directory. Currently, only gitk, qgit and git-cola are supported. If you want more git integration, you probably have to use KDevelop or QtCreator
As a quick notice: The highlight selection plugin was not removed in KDE SC 4.10.0. Instead, a silly bug results in not loading the plugin. This is fixed for DKE 4.10.1. If you cannot wait, you can find a workaround here
The project plugin in kate.git master has now the ability to call cppcheck.
This is just hacked in at the moment and needs more love, but it works.
Feel free to contribute integration of other code checkers, cppcheck is only the first, I hope