While most of the project went pretty smoothly, there were a few glitches:

1. I should have coordinated more closely with the electrician during the planning stage to save some hassles with swapping out electrical boxes, wiring, and associated components later. We ended up up-grading in this case, so that it probably is not a problem for the utility company.
   
2. I ordered more racking equipment than I needed. Proper planning could have saved me some money and some hassle.
3. We should have covered the PV modules with cardboard to prevent damage from dropped tools.
4. The heavy duty hook on my roofer's safety harness needed to be covered by some soft fabric--at one point it landed with a considerable impact on one of the glass modules.
5. Ready-made flashing might have been a better and neater solution than the on-site made flashing for the roof attachments.
6. In the future, I would not use the same theft-resistant fasteners I used for this project; they tended to strip out at the recommended torque levels from the racking manufacturer. If I need to remove the modules in the future, it will be challenging.

There were also positive lessons:

1. Extensive planning paid off with a pretty smooth project.
2. Purchasing a kit simplified purchasing and planning. I highly recommend purchasing a kit. Be sure of what you are getting, though--some kits do not supply the racking materials--a significant extra cost, especially for thin-fim photovoltaics.
   
3. It absolutely helped me to have class room and hands-on training from expert installers at Solar Energy International (SEI): http://www.solarenergy.org/
   
4. The guys at the electric utility and the town zoning board were helpful and supportive. Following the requirements from them minimizes hassle later. 
5. If you are not a certified electrician it makes sense to hire an electrician like I did.