So while I was looking into another problematic blend (symmetric surfaces that lead to asymmetric blend surface) I think I found the cause of the blend problems, or at least some of them.
When I invoke the surface blend command and choose for instance g2 continuity for both edges, that doesn't necessarily mean that under "advanced" the start and end continuities for the edges are set accordingly.
That was the case in example 01 (and the other problem I was working on): both edges were set to curvature and nevertheless end 1 was set to position (without me ever touching it).
So I don't know if this is a problem of my VSR preferences or, if not,whatever causes this behavior.And I don't know if this was the cause of all strange blend results I have gotten so far, but the least I can say this explains a good part of my surface blend problems.
Needless to say You should control the inconsistent behavior of the start-/endpoint continuity settings.
I think it is obvious these should only differ from the edge settings if they are actively changed by the user.
Ciao, Norbert