I've had my fun, and I think I've stumbled as far as I can go. To go further would mean hard programming, and my fans know I don't do the work thing!
To sum up: Cheap computers and clustering means that we can go to more elemental physics for our seismic analysis, much the same as the way the movies model all types of material behaviour, for our entertainment.
The compute-saving assumptions of the past are dangerous and misleading, especially once you wander out of California. For example, they show excessive amplification with stiff buildings on firm ground, which has never been observed in the field (Experience Data).
Further advances in explicit analysis await somebody with more energy than an old man!
I hope you all had as much fun with this series as I did!