I understand where you are coming from but I kind of like the small footprint that the current interface has, so instead of having additional visible quickbars, I would prefer scrolling through multiple quickbar mappings via the up/down arrow approach.
Merging some of the ideas together so far, perhaps a simple compromise would be to have these multiple quickbar slots available via scrolling and increase the AP as you go down each level. So if they gave us 3 quickbars available via scroll, there would be no additional cost for level 1, but if you scroll down to level 2, it costs you 2 AP in addition to whatever the ability requires. If you scroll to level 3, it costs 3 additional AP. That way your skills are still available even if you didn't happen to put them on your first level, but it will cost you extra to use them. It is similar to charging action points for moving abilities to your quickbar, but more flexible and requiring less constant manipulation.
