I have a lot of scripts that the 3d/gameplay artist on my team cannot use (abstract classes and such) and they are cluttering the project view when he is trying to find those scripts that are worthwhile to him.
Is it is possible to hide scripts from the Project View?
I don't think so. But why don't you create a folder structure where all scripts that are irrelevant for your artist go into one branch, so he can just ignore that folder?
What you could do is create an assembly(dll) of all the abstract classes and put it in the plugins folder. BUt that will only work for classes that are not MonoBehaviours.
Maybe you can try EditorUtility.CreateGameObjectWithHideFlags.