A good review, I agree with everything except for a few mistakes about the skill trees. Regardless, most of your points are completely valid, especially about world/npc interaction and influence and quest design, especially the guild questlines. A major disappointment, because it was done far better in Oblivion, and I expected at least the same in Skyrim.
I agree with your sentiment. The guilds in this game are an utter disappointment, one of the few areas of the game I am actually disappointed in. The College of Winterhold drops some serious lore mentions but never goes far into it. The rest are permissible but not to the quality and length that Oblivion or Morrowind had. I only hope DLCs add some factional depth and conflict. I find that Skyrim's faction quests whet your palette but do not go far to actually satiate it.
Speech is the other area that I felt really took a hit. Character interaction is all but useless, you are forced into questlines (Daedric, Thieves, etc.) regardless of your moral leaning. Those are honestly my only grips at this point, after 87 hours.