Just gonna respond to the OP, (who has time to read 44 pages). Though I'm sure someone else has echo'd these sentiments.
I agree that SQE should look at their base game and their new player experience going into ShB. The road has changed a lot and the bridge is out in some areas, so to speak. (The 100 quests of bloated nothing between ARR and HW needs to go.)
However, what I don't agree with the OP on is the absolute need for their friend to catch up "in time". I understand the desire to experience the expansion with your buddy and all the new content that you're getting. But it makes it sound as though they can't play together at all until that point. The OP just has to do his friends content, instead of the other way around.
Rushing the content is cheapening to the experience anyway. If the friend doesn't take the time to enjoy and get attached to the world of Eorzea, then the elements that keep the OP coming back to the game wont't be there for their friend and they may lose interest more quickly... For the friend, ALL of the game is new content, and there's plenty of time still to get to max level.