Fiorina the Horse Face doesn’t bring shit as VP. She’s a has been and her career is mostly fraudulent.
Take gender off the table and Hillary has zilch to run on. She won't be able to take on Trump directly, but if Cruz is on the bottom of the ticket, expect to see lots of demonizing of him as a "heartbeat away".
If Cruz isn't tapped as Trump's VP (still the preferred ticket for many here) then he'd certainly make a superb Attorney General with an eye towards a SCOTUS appointment at first opportunity. In any event, any such speculation is months premature at this point.