1. Cascading links always have at least three points, but in this case the last two points coincide and the hit-testing code tries to move the middle control point. However it is aligned to both end points, respectively by x or y, and refuses to move. We’ll see if we can change the points’ hit-testing priority for the next release. For now you could offset the middle control point a bit when you detect that the newly created link is a straight line (three points in ControlPoints either on the same X or same Y). Alternatively check how AllowSplitLinks="True" works for you; it lets user insert or remove additional link segments, and here would add a segment and let the user move it away from the last point.

2. Try setting diagram.RoutingOptions.Anchoring = Anchoring.Keep or Reassign.

3. Are you assigning to the Overview.Margin property?

4. I suppose you could add two thin nodes to the right and bottom of the diagram, set their Constraints so that the user can move them respectively only horizontally and only vertically, and set HandlesStyle to MoveOnly. If you also enable AutoScroll and AutoResize the user will be able to move them outside the current diagram.Bounds. Now from NodeModified you can set the right or bottom position of diagram.Bounds to coincide with these nodes’ x or y positions. Alternatively you could add two WPF Thumb controls aligned with the diagram and handle their move events to resize the diagram.

5. Probably the diagram’s ApplicationCommands.Delete handler stops Del from reaching the textbox. We’ll try to pass it through for the next release.

I hope that helps,
Stoyan

Hi, please try this build for 1 and 5:
https://mindfusion.eu/_beta/wpfdiagram252.zip

We are releasing it next week.