Intersting article Robbod, but there are a couple of points I would tend to disagree with. Primarily the feeding regimen you mention.
Juveniles should be fed five to six times per day instead of three. While adult Discus may survive on one feeding per day, mine get at least two.
Diet should be varied as you say, but certain sinking pellets can cause problems with bloat if not presoaked. Mine like flake, but I've stopped feeding it to them since I lost two beautiful speciments to a suspected tainted batch. HI protein is important, so lots of real meat, i.e. bloodworms and live CBW's area a good source. Ocean Nutrition makes some good frozen food to supplement witih that has various ingredients (mine like brine shrimp plus) though others swear by ON 1 and ON 2.
84 to 86 IMO is on the verge of being on the chilly side. Mine live in 88 or so and seem to like it much better. Wilds may like it even warmer since the Amazon isn't known to be a temperate environment.
Like I said though, overall good article, thanks for posting
Jim