I thought edge durability was more a factor of the bevel angle and how well the edge is used/cared for, not just plain sharpness. As such, I don't see sharpness as relating to edge durability on a razor.

I do not think there is such thing as too sharp. But some things can cause an edge to become harsh as well as sharp and I don't like harsh edges.

Smooth and sharp is what I shoot for.

You may not want to hear it, but if you loose your edge after one shave to the extent that you need rehoning, something is wrong. You don't have to send your razor out to be honed, but I do think it would be good if you could sit down with someone and get things sorted out person to person.