I like to compare my setup to a standard transmission - neutral is my goal. To go in either direction - I must "put it in gear". Really helps in gusts, as the kite doesn't just take off, all by itself. Yes the launch can be a bit more effort, but the control gained while airborne is well worth it!
As Paul said - everybody has to find their own "comfort zone". A lot of new fliers feel like they need that extra zoom they get with lines in. But the kite is locked into forward drive too much. Loss of control while airborne is the result. Moving the top lines out gets the LE to fall back. Then when launched, it is more "square" to the wind and able to keep all the energy in the sail. We call it "squaring up the kite". Top lines in, the wind just dumps off the sail, because the angle is too much forward.
Nice inverted side slides!! My only critique would be to let your arms out. Learn to fly with what other pilots call - "long arms". The kite doesn't respond to where those handles are in relation to your body, as much as how the handles are controlled by your hands. Forward is forward no matter how your hands are. Catch those adjustments moving the hands, but really try to get back to a more central position. Think about it ergonomically - if your hands are in the classic "fighter's position", how much movement backwards does that allow? Hands and arms are already close to the body and movement is limited. Now try arms extended some - see how much more you can move? And in more directions. Many of us fly holding the handles almost sideways! With arms extended, we have upwards, downwards, and sideways movement available. Try this - let the kite pull your arms away from the body. Feel the kite out there. Learn to work with it, not against it. That's your dance partner out there, learn to work with it.
PS: a side effect of "long arms" is that your tension levels will decrease! All that scrunching in the neck and shoulders will go away and you will feel relaxed!! TRY IT!!