Ok, about the fuse. I used a longish, precision, bubble level to establish the baseline. Picked the side of the fuse I felt best suited to the task and stuck with that positioning. Mark it if necessary so that each time going back was consistent. There are limits to precision as it is not a composite surface,+/- 0.1 deg IMO, good enough for what it is. Then realized that the more I tried, the more it was going to vary. For example, once I got it to 0.5-6 deg with the stock adjusters, I decided to leave it alone, even if it can be "improved upon" in theory. Could be that next time around would come out worse.
About the stabs. Once I got them zeroed, left them alone. When I went back to increase from 0.4 deg to 0.5, I leveled the fuse with reference to the stabs, not the canopy deck. I reasoned that since I did a good job on the stabs before, finding zero incidence there by leveling the whole fuse was more precise than repeating bubble level dance. Then used the bubble level to check my work, and on to reset the wings. That said, I'm not going back for 0.8 deg any time soon! Hope this helps.