That's not actually true; as it stands the delegates could cast their votes differently precisely because "what was sold" was NOT what's there. This could come out, say, during the convention. If, for example, the candidate was presented as a pro-life paragon of family morals and then made direct statements that Roe v. Wade was actually a Good ThingTM then there would be reason for the delegates to try to back another person.
To do so, should get them fired. They are selected, not elected.
See the above.
I probably would be against the changing of rules between conventions without a vote. But I’d have to see more info on it.
I'd definitely be against it; in such a case what's to stop someone from publishing a set of rules and then, as soon as the delegates are out-of-earshot changing them? Or worse, being changed in secret?
Again. It’s a bad precedent. What happens when a conservative wins the primary and then the delegates “find something out” and choose a RINO? Happy then?