Thanks for your explicit details about each of your requirements. Here's the list of answers for your queries,
Query 1: Layouting of diagram nodes.
Currently we donot have full support for layouting with multiple end points of OrthogonalConnectors. Only with multiple end points from OrthogonalConnectors we can have the output like you have mentioned.
Thanks for suggesting this valuable feature of "Using LayoutManagers with orthogonal connector fully" to enhance our product. We have logged it as a feature request and notified our development team. We will implement this feature in our forthcoming new version releases or service pack releases. We usually have a time frame of at least three months between releases. The feature implementation would also greatly depend on the factors like product design, code compatibility and complexity. We will get back to you once the feature is implemented.
Query 2:To get url-links on the nodes as it is now, but is it also possible to implement the "expand-nodes"-layout together with the url-links in some way?
The Diagram's inner Labels collection is a normal lable collection list. However, you can use the ControlNode to have any kind of control placed inside the node. In this case you can use LinkLabel inside the controlnode. You can have a custom node defined by inheriting the ControlNode and override the draw methods to give the expander look and feel.
Query 3: The size of the Model in the DiagramWebControl that is set to "SizeToContent"..
This property is newly included in our version 5.2. The model can be aligned such that it is sized to fit only the objects rendered on it, thereby eliminating any space around the objects with respect to the edge of the model. This option has to be turned on by enabling the SizeToContent property.
Query 4: Documentation for Syncfusion controls.
Here is the link to the online documentation for diagram. http://www2.syncfusion.com/ug/Default.aspx##Essential%20Studio.chm/DiagramBase/BoundarySettingsAndObjectArrangementOrder.html
I hope this will helpful for you find more information.
We have a beta version for v5.2 of ES. There is lots of new features added up in this version. There are some preliminary guidelines for using the beta. Please check the below link for details,http://www.syncfusion.com/support/Forums/message.aspx?&MessageID=67624
Or you can wait and get the final version of Essential Studio v5.2 going to be release very soon (mostly by this weekend).
Please let me know if you have any other details.