Unwanted rotation on the way up:
Carving too hard upwind with board or body
Unwanted rotation on the way down:
Redirecting too early and sending the kite too low
You *can* send the kite back as far as you like, but it'll produce more of a pendulum up (like jumping off a swing) than lift, and you'll have to have you redirect wired tight or youll get dropped.
Edging is more about holding your line than carving upwind: notice Dimitri just gives the board a little flick before take-off. Wakestyle, you want a big strong carve to load the kite and use the elasticity of the lines etc to pull you off the water.
I don't know where I send the kite to cos I never look at it. I think just behind 12 is good... and when it's there, leave it there.
A good boost will have you going up and down in a parabola... which will curve around with the kite as the anchor point. Going straight vertical with no movement across or downwind is harder to control initially.
Don't think about a single perfect bar position... it'll depend on conditions, kite trim etc. Let the kite fly.
Redirecting will soften the landing. If the kite is "behind" you, it'll come across the top of the window and supply a little lift, as well as giving a little downwind speed...
You'll need to work out your own timing for the redirect - kite will be a big factor. You can do it earlier (or later) if you redirect slower (or faster/harder). Kites with less float will need more aggressive redirects....
Sheet in on the way up and hold it till you touchdown. You can sheet out (then back in) just a little for the redirect BUT if you sheet out too much, the kite will zip across the window and pull you off balance and drop you like a stone... which can be fun too
Spotting your landing is vital because you judge the redirect timing from height above the water.
The basic technique should serve you well for any height.