Hi,
The fact that query includes hippostd:publishable , hippo:availability etc. makes sense because you’re looking for documents, not for compounds.
The query has: and (@ftcore:date_valid_until____day >= ...
but you should aim to have something like and (ftcore:CoreMetadata/@ftcore:date_valid_until >= ...
Again, if that doesn’t work, use a derived data function to copy the property to document level so you can use that.
HTH
Jeroen