First, let me start by saing I had a great time! I look forward to doing this again!
I came in the first time with a lvl-2 Bard. It was my understanding that the quest was geared for "all levels". It was quite apparent within the first few minutes that the low level characters were signifigantly handicapped in this event. As has been stated many times, the high level clerics/wizards came in and killed mobs with area spells (mass heal, cometfall, etc) just as us low-levels had finally beat down the zombie we were fighting. I don't think most of it was intentional by the characters, they were going after the high-level monsters in the area. After 45 minutes of play, I had only 2-3 kills.
I came back in on a level-17 bard, and had more fun. More kills, more collectables.
Things I would like to see changed.
1. No ability to get Bard Songs or Clickies back except to exit the area back to the tavern. The coffee was a nice touch, but would like to see something that will help with songs. Not sure if it's "fair" to force just one class to leave the area to get a primary function back, while casters and melee can get an item inside for regeneration. Maybe sell an instrument, or 'guitar strings' or something like that in the store to get the songs back.
2. Think about setting up instances by broad levels, to give the low levels a better chance of actually collecting items. Or giving us the option to enter higher level areas
3. Some kind of ability to determine the CR rating of a monster you are about to fight. This didn't bother me that much, but if you have new players participating that have never fought a Frost Skeleton before, it can ruin their day

4. For players that have little/no DDO store points avialable to them, the lack of being able to get coffee or keys in the event could be a big turn-off. Not sure if those items are tradeable, as I never tried, but perhaps allowing at least the coffe to be traded would probably be helpful.
I had to leave just as the 2nd part was starting, so I can't comment on the rest. I really apprecaite the time/effort Turbine and the devs have put into this, and, as I said, I look forward to doing it again!