1) Did you have experience with migration of the diagramming solutions from iLog library to your control? Do you have a migration guide?

We don't have experience with that unfortunately.

2) Can we have any type of shape to have the capability of the container node (Group)?

Try the ContainerNode class, or DiagramNode.AttachTo method.

3) Can the port (or connector) be created on the border of the shape automatically in run time, when the user drops the link's connection point on the border of the shape?

Set Diagram.AutoSnapLinks and links will connect to any point of nodes' borders anyway. Otherwise you could create AnchorPattern and AnchorPoint objects from LinkCreated event handlers if you need to create such points explicitly.

4) Can the user manipulate the ports (or connections) with the mouse in run-time (move, delete, duplicate)? For example, holding the SHIFT key, while moving the mouse, moves the port position. Holding the CTRL key duplicates the port.

You can select a link and move its end points freely without modifier keys. If you need to define such ports / connection points explicitly, it should be possible with some event handling.

5) Can links connect to other links?

They can't. You could possibly attach a small node to a link and then attach other links to that node.

6) Can we have the windows control to be embedded inside the shape? and be interactive? For example, we need to have editable text inside the shape and capture events, when the text is modified. Also, we need to have the image inside the shape, so that a user could choose the image in the run-time.
What's the best approach to achieve this functionality?

You can host any Windows Forms control inside a ControlNode.  If only for editable text and image, better use CompositeNode. E.g. check EmployeeNode.cs in the Demo sample project or the node types in Scripting example.

7) The iLog provides the "selective printing" feature out-of-the box. It means that in their Print Preview dialog the user can visually select the area on the diagram page to be printed, or enter the position of that selected area in the text fields. Do you have a similar functionality?

We don't. You might try setting Printable = true or false depending on whether items are inside selection rectangle to achieve something similar.

8) Is the ActiveX version of the Diagram control fully API compatible with the WinForms .NET version? Do they have the same feature set?

We've redesigned the API for .NET, it's quite different (e.g. ShapeNode in .NET is Box in ActiveX, DiagramLink is Arrow, etc). The features are roughly the same otherwise.

Regards,
Slavcho
Mindfusion