Im Fine Daz, its just that I have only just switched the computer back on again after doing some jobs at home!
The vids look good matey, its just a pity you still havent got sufficient "calm/smooth" water to get several passes in. Looking at the videos it seems the major times the boat gets twitchy is when it travels over its "old wake/s" in the water, if you find clear water she's a flyer!
As for the "left drift", do you think its simply the "torque twist" from the prop?, afterall there aint much of anything else left of the boat in the water, is there [LOL], if you deepen the turn fins, its only going to add drag again and no doubts you are trying to reduce as much as poss.
Or is it better to limit it now and at least you have a working design and know its limit, without pushing it over the edge [hope you dont - again].
I'll email you direct about the advertising, but you may have to work sharpish to hit the print deadline!