Hello Matt,
If you want RadDockZone to resize when add RadDocks you should set only RadDockZone.MinHeight property instead RadDockZone.Height property. You can find a simple example, which illustrates zone without scrollbars (second zone) here:
http://www.telerik.com/DEMOS/ASPNET/Prometheus/Dock/Examples/ZoneOrientation/DefaultCS.aspx
Regarding your second question, the RadDock has a Height property and it can be easily controled on the server, e.g.
RadDock1.Height = Unit.Pixel(400)
As for your last question the answer is no. The RadDock control is a child of the document, e.g. it cannot be dragged outside of the browser bounds.
Let us know if you have any other questions.
All the best,
Petio Petkov
the Telerik team