Hey Tieku,
Look what I've done to the navbar. That's in the database but may be doable in the quiz too. Would something like that work for you until the wonders of 2.0 become available?
Itamar Tzadok
Posts made by Itamar Tzadok
In the meantime you may be able to workaround that if you hide all these quizzes in the gradebook and then create 5 gradebook items, one for each pair of quizzes, and set the item's grade to be the sum of the respective quizzes.
Add random in the quiz edit page. See image below. 
Well, you could also suggest to the students to select "allow pop-ups from this website" (or something of the sort depending on browser or blocker) which will add an exception to the blocker for your site and prevent the need to override the blocker in each and every attempt. Hope that helps.