I cant help with the serrated part, but my 806 was sharpened on sandpaper, and then a belt sander. I recommend a LOT of practice before moving to sharpening an 806 on a belt sander. Thats the reason it went back to BM for a new blade.
I'll add the usual statement of try a magic marker on the edge and make sure you are hitting the very edge and not just grinding on the shoulder. A 10x jewelers magnifier helps, or a pocket microscope from radio shack. If you really have edge OCD, then a benchtop binocular microscope is great, but few (not even me) are that picky.
If you have diamond benchstones, I'd recommend making a jig to hold them to match the angles on the sharpmaker. I use a 4x4 cut in a miter saw to 12 degrees and 17 degrees, 3 degrees less than the sharpmaker settings, so all the sharpmaker has to do is remove any remaining burr and then micro bevel the very edge. In hindsight, perhaps a difference of 5-6 degrees would be better, but 3 has worked all these years, so why change now. The 4x4 is then screwed to a 1x6 base so it sits vertically, and you can use the same motion as with the sharpmaker, just one side at a time. I suppose you could get another stone and make a big benchstone version of the sharpmaker, but I've never bothered. The 4x4 is slightly longer than the stone, but how much is not that critical. I use duct tape over the serrations of the knives I had that were combo edge. This gave me a stopping point before ruining the serration and protected my fingers. You could also use the lower angle jig and diamond for backbeveling, then use the higher angle jig and diamond for a few finishing strokes, though that requires moving the jig after every stroke. This should give a toothy edge, which is what D2 is known for, and you can skip the sharpmaker altogether. This is how I got my hair whittling coarse edge on my kitchen paring knife, using an 800 grit waterstone. If you have the diamond triangles for the sharpmaker, then disregard all this and use them and the triangles for best results.
