After weeks of frustrating crashes, often minutes into the game, and then minutes again after the next login, and so on, I just played a thoroughly enjoyable session of ESO, and quit when I had enough—not when the game 'decided' to crash.

What made the difference? I read the list of graphics settings recommended by KhajitFurTrader (original thread can be found here), and applied those settings.

Graphics quality: Custom (modified from Ultra-high)
Texture Quality: High
SubSampling Quality: High
Shadow Quality: Medium (down from high, the single most performance improvement)
Water Reflection Quality: Medium (default)
Max. Particle Systems: 1024 (default)
Particle Suppression Distance: 50 (default)
View Distance: 60 (down from 100)

Everything else is ON, with the exception of VSYNC, which is and stays OFF.

Additionally, I did the following, as suggested by Zeni's own chris.dillman (note that this is a Mac-specific fix):

Find eso.app in the finder.
Select it
Chose: File Menu / Get info
Turn on Prevent App Nap.

My gut tells me that it was the adjustment of the video settings that did the trick, but who knows—it could have been the combination.

Only a considerably longer play session will tell whether my problem is definitively solved, but that in itself is encouraging given that, as I said above, ESO kept crashing on me minutes into the game.

So, a big hand for some truly constructive contributions to these forums.