Criddy,
I just looked at binary behaviors in the MSDN documentation. It should
be possible, since they are nothing more than COM objects, but it will
require a lot of COM interop on your part. Unless someone has created all
of the definitions, you probably have a lot of work on your hands.
As for doing everything you can do with C++ in C#, I haven't come across
anything yet that I couldn't do (without any serious workarounds as well).
Unless you are trying to write device drivers, I would say there is nothing
you couldn't do in C# that C++ could do (except the obvious, like export
functions from DLLS, stuff like that).
What is it that you are concerned about or trying to do?
Hope this helps.