Hello! We'll reply as for the current intention of the rules. Feel free to continue discussing.
1. Yes, you are allowed to measure before choosing your action, except the Charge action. That means if you start measuring, you can't Charge.
2. The idea is that you can only sprint into your forward 180 degree arc at each move, without changing facing before the move (only after) and at the end of the spring you must stay faced within the same 180 degree forward arc. We'll clarify.
3. No, the move requires ground to move on.