Took me over a year but it's finally finished...much appreciated all the input! Got lucky with the chain line. I screwed in an old Shimano square taper bb with 110mm spindle just to see how the chain line would play out and it was perfect...a nice surprise. A shade over 12kg; not great but not terrible either.
Looks good! I'm jealous of your front disc brake, that eliminates rim sidewall wear. I've seen that front rack before, and the only thing I don't like, is the aft portion of the deck supported only by the center bolt in the fork crown, I'd prefer some vertical struts there like in front; Lateral offset loads there will try to twist the rack deck. At the front of the deck, fine, fully supported. But the further from the fork, the more the weight affects steering. But keep the aft load balanced left and right, and you should be good.