No apologies needed, I hope this adds to the OP database -
Oh yeah, chain hit tire and chain hit chainstay. Tensioner fixed chainstay hit, 26 x 2 tire fixed tire hit.
I violated all the rules with my sprocket mount. I have it dished out and spaced with the 2 thinner steel plates (5 hole / 4 hole) off the spokes. I cut the rubber donuts 5 hole / 4 hole also as they were uneven thinkness. I took the sprocket to a machine shop and had them cut the center hole to 1.53 so it fits perfect and is held concentric by the dust cap on the coaster brake. So good, so far, no problems with wheel / sprocket. The benefit was I didn't have to spend hours tweaking the bolts to keep the sprocket concentric and wobble free, I just torqued up the 9 bolts and that was that. I did have to turn the brake arm over, heat and bend to clear the bolt heads and I also ground a few thou off the tops of the heads.
Yeah, hours and hours...