Aside from what VJ Air said:
What I'm trying to accomplish is to have my effects clips layer be the only one that is showing - e.g. instead of having the original video showing at full opacity on a layer below.
Effect clips can never be the only layer showing. They need some input to work, because they are essentially just effects An effect applied on nothing looks like... well... nothing
You can however set the opacity of the effect clip layer to 100%, so you see *only* the final result of the effect applied. For effect that generate an alpha channel (pixels in space for instance) you can check the Black Background box to render them on black.
In VDMX I am able to hide or show a layer but leave it active so that I can use it for masking another layer. Is this possible in Resolume?
We are playing around with implementing a routing system such as VDMX has. How, when and if this will make as a feature is very much up in the air at the moment.