Mr Light wrote:
""Also, and this is a biggie - WHO BUILT THE TEMPLE OF THE FIVE? Why was it built after the final five rolled through town?"" As I vaguely recall this was addressed in the Ellen/Cavil flashback episode. Cavil said she and the Final Five created the temple or altered it to be a road map to their Earth or something like that.
The thirteenth tribe built the place on there way to Earth (they called it the "Temple of Hopes").
Most of that can be found in "No Exit."