Based on your screen grab, it looks like you've installed MSYS coreutils 5.97-3. If that's the case, you'll also need the coreutils-5.97-3-msys-1.0.13-ext package (which includes pr.exe).
This may also fix the dxva issue, otherwise try moving the header file to the MSYS/local/include folder.
As for the Qt issue, if you run "export" again, is the QTDIR variable set correctly?
It also looks like the version of MinGW you're using is probably too old but we can tackle that once you have the CMake process sorted.