I've posted here, perhaps, or elsewhere that I have this same problem. My solution, dig out your old copy of Keynote'09. (v5.x)
v6 will export to '09 and, while you may have to make repairs (two Magic Moves were broken as they were text objects so I converted them to tiffs), you'll find the excellent QT export options of Keynote '09 provide anything you might ask for. Choose from simple defaults to custom output... pick your Frame-rate, Key-frame-rate, Data-rate, image dimensions, quality (low to high and one-pass or two-pass. And all timings are preserved.
Everything that Keynote v6.x should have kept. Can't figure out why they feel that had to change this feature.