One question though when flying the kite up and down to generate power I was sheeting right in to turn the kite, once it's turned and is coming down through the window will you get more power if you sheet out at this point or best to keep sheeted in?
When sineing the kite up and down you can sheet in more on the down stroke and sheet out more on the up stroke. The kite has gravity on it's side coming down then against it going up. This is more apparent in lighter winds. The kite is easier to stall going up and you can get a little more power with it going down.
In general you just want to get a feel for the power coming through your harness. Maximize the pull at the harness by flying the kite as fast as possible with just a little bit of bar pressure or sheet in. Gentle turns and don't pull on the bar too much. Longer lines can really help make this easier.
Also I was amazed with how far overhead the kite would fly, it did overfly quite easily, each time it drifted back and could be recovered but wondering if you want to avoid overflying is it best to keep sheeted in or out when it's above you?
Sheeting in will prevent or reduce overfly. You can even backstall the kite to position it as deep in the window as you like. Most experience foil flyers will have backstall on their bar for this. Oversheeting can also give some extra little power boost and tighter turns.
Also note foils drift best directly overhead. If you position them there they usually have no issue. You can even end up way downwind and they will come back with little issue. I have done stuff like end up 10m downwind, even managed to drive a kite on short lines upwind back onto the water.