Good to hear from you. My trip to Tibet was wonderful. I have traveled all over China and enjoyed the differences of Tibet. Everything worked out as expected. Thank you for arrange train from Xi'an, it was no problem getting my ticket.
The 7 Sages Youth Hostel you recommended was very nice. Keep recommending it. Our tour guide Pen was very well organized and ran a good tour.The Lhasa hotel was good and we all enjoyed the big western breakfast there each morning. We liked how close the hotel was to the market and good restaurant. My only complaint was minor and we took it up with Pen that our driver seemed to lack focus and had trouble staying alert and would always fall behind the group of three vehicles that we shared. This was minor and just something to keep in mind. It did not take away our enjoyment of the tour.
On the last day when we returned to Lhasa, a small group of us walked to the Tibet museum. It was free and nice and did not take long to tour. You might think about adding this on the first or second afternoon to end there and let people tour on their own and then be free for the evening from there. Our group took taxi back to hotel for only 10 Yuan.