RE: the 30 knot day...
I also have problems getting in the back footstrap so i usually place my foot in the centre. However, when the board starts bouncing around a bit, it's safer to put in on the rear strap in the beginning, to get the feel, later u can then put it in the footstrap, once you find the propper position to stand in.
What fin did u use for the 5.0? Whenever i put my 5.5 on my go i use a 40 cm fin (a bit short but i've never had a spinn out with it).
You sailed 30 knots with a 5.0? .... dude .... Even i wouldn't try that, i might use it in like 25-26 knots ... and even then i'd be taking risks, especially with the go.
Haiko, AKA crazychemical