The NewLineStyles node is partially built which means it is currently outputting null (nothing). Using that as the input to the DetailLinesFromCADLayers lineStyleMap input is therefore invalid hence the error.
Issue 2 will arise once you fix issue 1 as the NewLineStyles node outputs GraphicStyle objects but the lineStyleMap input takes strings (text) so you will need to connect the GraphicStyle output into an OOTB Element.Name node to get the name(s) of the line styles as strings first.
There might also be a dependency issue with your workflow too as the DetailLinesFromCADLayers node will execute while the new line style is also executing and Revit might not register the change, creating a ‘cyclic dependency’. Since the NewLineStyles output forms an input to this node however, Dynamos VM should be able to handle this scenario. If you do get errors create the new line style first, then run the DetailLinesFromCADLayers after.
Also, your importInstance input is invalid. You need to connect the Select Model Element node to this input. CADLayerNames outputs strings. Visit my YouTube channel for guidance: