To work with the SolidWorks API you would need the two following references:
I do a lot of programmatic modelling in c# and have never needed any other SolidWorks references.
Forget about adding the references from your local drive,
Use this nuget package to get the right references for developing solidworks add-ins.
> Install-package CADSharp.SolidWorks.AddIns -Version 2018.0.0
This will add the 2018 swpublished, swconst, swcommands, sldworks interop libs and set the embed interop types to false which is something you will need for CLR4.