Although these have all been suggested by others I would like to share my personal top 5 in order or priority !
1. Lobby enhancements (pre race chat)
2. Rule 18-19 where the obstruction is a land mass. VSK needs to recognise land as an obstruction to which Rules 18.5 and 19 apply, and a provision to hail is required so that the boat hailed must give room or be penalised.
3. Rule 18.2 - Inside overlap at a mark. The rights under this rule seem to end rather prematurely, and certainly before the rounding maneuver has been properly completed. Bearing away or gybing around a mark normally causes a reduction in speed. This allows a boat that was clear astern to establish an inside overlap when I have passed the mark but am still within 1 boatlength of the mark and have not properly completed the rounding. VSK then suspends my rights under 18.2 and gives the opponent rights under Rule 11 if I am bearing away, or under Rule 10 if I have gybed onto port tack.
4. Wind shifts to move across the course area, and not affect whole course at the same time.
5. Damage inflicted on the boat without right of way and then slows a damaged boat down !
Oh and a career log book mode that records a skippers successes and failures and make it available online.... yeah I know that's 6 things :p