Re: 5 down.
ENTAIL can mean a limitation of the inheritance of property to certain heirs over a number of generations.
Is it a coincidence/red herring that "hard to leave" could describe this?
Re 5d, surely the parsing is straightforward. Female only is Hen (as in Hen Night); take H away (“hard to leave”). Private Eye gives Tail ( see definition 21 of Tail as a noun in Chambers. Occasion (as in Cause to Happen) is the definition.