In 1.4.x I think that teachers could always take a quiz even after they had taken the quiz the limited number of times.

Certainly in both 1.4.x and 1.5 teachers/creators can take a quiz outside of its open time.

I think that creators should be able to test a quiz at any time

Ideally (and this is a seperate issue) there should be a warning to the effect Students can't take the quiz now - but you can Students can't take the quiz more than X times - but you can