is this possible? on a windsurf board there is enough float to jibe and tack even without any speed. How do you do this on a kiteboard? Do you send the kite to 12, pull the bar to get some lift and then just rotate the board under you?

YEAH POSSIBLE
PIVOT TACK OR PIVOT JIBE A HIGH NOON (DRIFTER)
JUST DO THE THE SHUFFLE AND HUSTLE THE BOARD AROUND

If you have small enough fins (or no fins at all like on a skim board) you can just kick the board around 180 deg while you are supported by the kite overhead. You can tack like this while stopped. I do this with my Mako King strapless which has fairly small fins compared to a surfboard.

If you have multiple bigger fins like on a raceboard though I think you'll have to have some forward motion of the board and actually turn the board as it goes through the water. You can't just kick it around be cause the fins will stop it.

There is no reason why you couldn't do a flare gybe. Weight on the tail, press the outside of the turn rail and run to the middle of the board to stop the rotation so you will get going slightly downwind and you're done. They are rather short but thick and wide so it will support you for lill while at very low speed. But you cannot turn it around an axis like around the mastfoot of a windsurf board. Anyways we were seldomely do that towards the end, just when you begin.

Here's a vid with quite a bit of tacking, on Airrush Sector 60:

http://www.youtube.com/watch?v=EScZRdfJ-lI

There is a real lack of good vids out there showing top guys racing, tacking, gybing, steaming of the wind on raceboards etc.
This is just my humble effort, on a light wind day.

One minute in..