RE: carve 90 2004
I think, with your weight and 5.8 you can start planning around 11 knt, perhaps a bit more. If you want to progress in lighter winds i always say, per BFt you add and extra m?? or take on off. So less wind, e.g 7 nts, you can take out a 7m?? sail. But i think you cant go any higher because of the boards capacety. Though with a sail like that you are more likely to have spin outs etc .... You can check the old starboard website (just to go the archives of 2004) to see the specs of your board and what starboard recommends.
All the rest is a matter of guts and testing... just don't in trouble :d
best of luck
Haiko, AKA crazychemical