RE: Upwinding a pure wave board
I'm the same weight as you are and have owned all of all of the Surf/Acid line starting with the Surf 78. The main thing is to be well powered up and don't let your speed drop. Keep lots of pressure on the mastfoot and be light footed with your back foot. I also like shorter harness, 24-26", lines for working upwind.
Waveboard also are quite sensitive to how the sail is tuned. Not having a enough downhaul can really affect how well you can go upwind. Also stick a bit larger fin in it than it came with until you get used to it. I highly recommend the new Drake wave fins.
And give yourself some more time to used to the board. I remember the first time I went to Hawaii and sailed my first waveboard. I couldn't believe how small the fins were and I spun out a lot until I got used to it. Once you get used to the Acid 80, it will go upwind better than you can imagine.