Thanks for reporting. It's been fixed. I'll release a big fix version soon.
Good to hear that. Thanks!
My previous tree view patch that was accepted in FC 0.17 has partially fixed the problem described in this issue. For example, a newly created Cut object will not steal children from other tree view item. And if the Cut is deleted, it will not affect the order of its children in other groups.
Support user defined ordering is kind of tricky, because each object has their own way of storing children. For example, PartDesign::Body already support this, but it needs lots of extra logic to handle this correctly. My A3 workbench supports reordering as well, because it knows how the children are stored, also because order is important in constraint group. To add a general reordering function is going to be hard.
We can, however, offer alphabetical sorting functionality without actually change the children order in the object. Simply ask Qt to sort the tree view items, but we'll need some API to enable/disable is function, because sorting does not make sense in some object, like Body.