1) I appologise, I no longer have the link. From what I recall it is only a thc increase. The other chemicals occur when thc degrades due to UV. In a dark period no UV light, or any light for that matter, is present. So only fresh trichs are produced.
2) Are you aware that most all of these nutrients that you desire to "flush" out are immobile? You may clean out left over nutes in your media, but the nutrients in the plant only move in one direction; up. Nutes cannot defy gravity and cappilary action within the plant that forces things up into the plant, not down and back out of the roots. Nutrient deprivation is all that you do by "flushing". I just feed water the last couple weeks so the plant can use all the nutrients already stored within. You are not flushing anything out of the plant.