There are so many problems with your code I don't really know where to start. Two of them are your use of IHasModel, and the fact that you are initializing your Item, Block fields statically.
Remove IHasModel completely. Use your list of Items/Blocks to register the models in the event.
Initialize your Item/Block fields in the registry event.
Remove ItemBase and BlockBase(if you have that). There is already a base item/block class. They are called Item and Block.
The Idea of a CommonProxy is already handled via the main mod class. The correct way to use the Proxy system is to have an interface(a lot of the time called IProxy) and two classes that implement it ServerProxy and ClientProxy.
Also I don't think you own the domain rnh.com so you should switch your package naming convention.