Chris,

Well, 2.5, not 25 years, in your model, but otherwise accurate.

We have a test with well-known stresses in the tides, that load most of the Earth with tides of 0.01 bars twice a day every day. Clearly far above the tectonic loading rate.

However, there is no evidence that earthquakes are more correlated with the tides where the loading rate is slow than where it is fast.

Chris Scholz, in Nature a few weeks ago, argues that the LONGER the time a given stress is applied, the less effect it has. He cites results of lab work by Nick Beeler and David Lockner

My own works suggests loading needs to get to 0.1 bars to be important, whether the loading rate is fast or slow, but many questions remain.

John