The errors you are posting are quite normal, as I didn't remove lots of API that are compiled for the desktop (but are not used my metro app. For example, the namespace Design that is generating lots of errors and is only used on desktop but can be removed easily). Keep in mind that the SharpDX 2.0 assemblies for Win8/Metro are a preview... SharpDX will probably pass certifications as all the API is using authorized COM/Win32 API. Though there are couple of things that still need to be clarified about the new 4.5 core assemblies...
The preview version is probably not entirely cleanup up from some CLR/Win32 functions that are not supported by Win8 metro, but that will be easy to replace them.
Using SharpDX, you will be able to use it from desktop as well on Metro, without to change your code.
You should better leverage on the unique features of your wrapper instead of bashing around existing wrappers. We are all on the same boat.