1- Yes, after the tack of green orange has the right of way. Green needs to tack in a way that does not hinder orange, so wait until orange also tacks or ga faster/slower to get enough room for his tack.
2- no in-course marks used as i know of, only a port-rounded upwind mark, a downwind mark or gate and start/finish line. Sometimes a spreader is used at the upwind mark.
3- yes, normal sailing/kiting right of way. Only odd thing is that we go 30kn+ on 150deg+ angles.
4- port-rounding solves this odd situation, in wich orange needs to tack twice to round the mark but can block green on his second tack if he stays in front of him. At least, that is how we deal with situations like this.
Having a kite makes some funny racing situations since you can block a rider coming from behind by keeping your kite low but on the other hand you can squeeze yourself through very tight spaces if the other racers forget to block you with their kite. A thing that is not possible with others sailing crafts.
Here the instructions and course from the Hydrofoil protour Mauritius:http://hydrofoilprotour.info/wp-content/uploads/2016/03/2016-Hydrofoil-Mauritius-SI-v3.pdf