I'd vote, but there aren't N/A options for questions 3/4, which I would really like to select
To me, it just sounds like one more thing to go wrong.
I don't know the innards of a freehub except for profile hubs, but unless you made something very precise to fit into the ratchet ring, it's gonna have some play in it, which would feel pretty horrible.
Solution:
Buy a decent freehub or buy a decent fixed hub with a freewheel.