Croossed lines can not be seen other then checking the lines. There is no sign for this from far away. In this specifical case you mentioned it just happend to be the cause.
Greetings, Sylt Rider
This depends upon the way you cross the lines, since you can cross the lines on one side or on both sides. I don't know which one is the worst...
A dancing kite can often mean a bar inversion. I saw a guy in the water, that was trying to relaunch its kite, the kite was then at the edge of the window, in a perfect position to relaunch, and I saw the kite dancing on the water and the guy being dragged a bit to the sea. After some times I went to him, he felt angry against its gear (what the hell of bar, f*** kite! this is shit! ...) I suggested him to turn its bar and he got back his smile in the second.
Remember that when you setup your bar downwind to your kite, you have to invert your bar. And this is the same kind of situation that occurs when you untwist your lines when the kite is leading edge of the water. (but now you are upwind to your kite, and it takes wind). Clear color codes are very helpful in that case !