The majority of my Red Osier arrows are snakey to some degree. It is rare that I get one that turns out perfectly straight, though it does happen. As a result, I have quite a bit of experience making snakey arrows, and I can say for a fact that they fly great!
I start by hand straightening my osier shoots as they dry. This removes any large bends in the shaft, but leaves the small 'snakey' bends. When doweling, I use a scraper (rather than a planer, which is what I use to reduce the straight shafts) to reduce them to the desired diameter. The point end needs to be straight for at least two inches to allow for proper point alignment. Since the point end is the lower, or larger, end of the shoot, this part is usually pretty straight. The smaller end of the shoot, which I use as the nock end, is usually where the snakeyness is. The nock end can be quite snakey and still fly just fine. A conventional fletching jig won't work, so I tie my feathers on, and use a spiral wrap to hold them in place, so they conform quite well to the curves in the shaft. As long as the nock, the point, and the center of the shaft spin true, it will probably fly straight. I don't use a spine tester; I spine by hand. As far as nock and cock feather orientation, I sight down the shaft and decide based on what looks/feel right. I'm sure expeience plays into the equation, as I have made quite a few of these arrows, but it isn't difficult to get the hang of it.
I don't have a camera, but I'll see if I can borrow one and get some pics of my snakey arrows.