I read more carefully this thread and found that this issue had already been reported.
- removing several cusp nodes e.g. of a default star converted to path:
I have some doubts about "fixing" this. There are two actions: delete while preserving shape (Delete) and delete without preserving shape (Control+Delete). Why should the first one cease to work when operating on linear segments?
Well, it depends on what you think "preserving shape" does mean: to me it means that a straight line should remain a straight line. Try drawing a single straight segment, then ctrl-alt click to add a node inside it then press canc: you get the original segment that has been turned into a (straight) curve. I don't think this can be said to be preserving the shape. In conclusion, I think that if a path is straight-segmented, preserving its shape means keeping its segments straight while turning them into curves is changing its shape. So, under this assumption the old behavior was correct and the new one is not.
Regards. Luca