This information was obtained by Geraldine in a private session on January 23, 2013.
1) One thing I'd like to pin down with a clarification would be "Is it standard for Essence to burn all ribbons of a Soul Age before moving onto the next Soul Age?"
In response to the first question: no. There is no standard. As Soul Age progresses, each Essence tends toward that as part of transition. This is, in part, because the Karma requires less and less strategic logistics and Agreements and conditions for burning.
After the mid-Mature Soul Level, a great deal of Karma tends toward the Emotional and Intellectual, and thus can be burned either between Personalities in waking state, or Astrally.
Though it is not a standard, many Essences do prefer to burn as many Ribbons remaining from the Young Soul Age as possible before entering the Mature Soul Age because those Ribbons from earlier tend to carry with them conditions that require more strategy, logistics, Agreements, and bodies for fulfillment.