I think directX toolkit was develop by Shawn Hargreaves which was on the xna dev team. The project is open source so basically you can just have a look at it and you'll find what you want to understand.
Also you can extend, add, modify the feature you want. You are not lock up in the design.
If you want to stay on c# sharpdx is a good alternative. It's a thin wrapper on top of directX. I managed to follow frank luma directX book ,which was written for c++ user, and the code was pretty close to sharpdx.