Registries and ICANN do require registrars to include certain clauses in their contracts with end-users/registrants, but I'm not aware of any that include vague morality clauses. This document - http://www.opensrs.com/docs/contracts/exhibita.htm - is an enumeration of the terms and conditions that ICANN and the registries require us (Hover/Tucows) to include in our contract with our customers/registrants. These requirements aren't specific to us.
I was in the room in the late '90s when most of these clauses were negotiated and then again in the early '00's when the new registries came online (Afilias, Neulevel, etc.) and most of the new registries just simply absorbed the existing T&C's in order to smooth out the approval process associated with them launching their new TLDs. They've grown and evolved in the last ten years and aren't as uniform as they once were, but generally, you can still see the pattern in there.
Generally, most of the power a registrar requires to prevent the bad guys from doing bad things comes from national laws and not all these extra clauses. We (Hover/Tucows) find that all these extra conditions just make it harder for our customers to do business with us and so we've left out as much as we can and rely mostly on national laws to get what we need done.
know 'em when you see 'em, huh?