economy is slightly better with stage 1 mountune, my work drive is only 6 miles so hard to notice (30-33mph), but others who drive further say it is definitely better.
My PZero now 7500 miles and no significant signs of wear, it's all about your driving style, I don't go hard around bends or roundabouts so I don't wear tyres out. Very happy with stage 1 and the lower down bhp and torque it has over stage 2. Would be only worth getting stage 2 if you like to rev it everywhere and await the big surge of power it has up the rev band then the stage 2 really takes off. Below that both cars are pretty well matched.
Insurance, Adrian Flux, no probs, just added £36ish.