"there would be about a week of continuous shakin"
Nice analysis. Thanks.
Let's take your math to completion for the San Andreas Fault. The San Andreas has a recurrence interval of 140-160 years and apparently a maximum earthquake size less than 8 ( both the 1906 San Francisco and the 1857 Fort Tejon quakes were magnitude 7.9)
By your numbers, a week of mild shaking would make the San Andreas "safe" for the next 150 years.
I am certain that California's engineers and first responders would gladly sign up for a week for continuous "fives" if, in return, we could declare the San Andreas "safe" for the next 150 years. Remember, any given "five" is felt over a much smaller area than an "eight", so no one locale would experience your "week of shaking." It'd be more like "hours of shaking" , after which that fault would "safe" for decades to come.
Even better, and closer to my original remark, would be replacing that infrequent "monster" magnitude eight earthquake with a modest modest magnitude 5 earthquake somewhere in California ever other day. Indeed, Southern California experiences a few magnitude 5 earthquakes in a typical year, and no one seems to mind too much.
Last I studied this (and I admit it's been awhile), the dangerous faults were those with "sticky" sections, where great strain could build up. Faults that were "smoother" with more frequent, smaller earthquakes were considered less dangerous.
The strain builds inexorably along California's faults; that stored energy will be released. The only question is "how?" As your numbers indicate, numerous small quakes are preferable.
Thanks for helping out.