Thank you for writing and sorry for the delayed response.
In regards to your first question, could you please try using the following declaration of your stream:
Additional information regarding saving and loading layouts can be found in this help article.
With regards to your second question, I can suggest you to remove the floating option from the AllowedDockStates
collection of the tool windows. Please consider the following snippet:
ToolWindow1.AllowedDockState = ToolWindow1.AllowedDockState
Information about your last question can be found in this help article - Using the DragDropService
I hope you find the information above useful. Let me know if I can assist you further.
the Telerik team
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