Using C++ instead of C# ?

I prefer to code my projects in C++ rather than C#.
Is it possible?

Can I include C++ code in C#?
Can I dynamically call a DLL from C#?

Basically yes. Since C++ also provides a .NET version of C++. However programming for CIL works a bit different to normal C++. Also C++ isn’t directly supported so you would have to compile to a .NET assembly and add it to your assets. I strongly recommend to use C# instead.

Beside the true scripting support, if you have Unity pro you can use native code plugins (except when you build for web) which can be written in normal C++. However the interaction with the Unity API get’s very complicated. Stick with one of the 3 supported languages.