Hey Adflixit-
It is possible to add new classes through Visual Studios by adding new files to the solution. The benefit to adding a class through the editor is that it will setup a lot of the required code automatically (includes, UCLASS, constructor, etc). However adding classes through the editor will trigger the code to compile, so if you are trying to avoid this you would have to create the new file through VS and setup this information manually.
Cheers