Thank you for the suggestion. Currently, this is not possible but I logged it as a new feature request in our PITS and updated your points.
Here is a direct link to the PITS item:
By the way, regarding the glitch I talked about in my previous reply, we found out what is causing the problem and although the internal logic cannot be changed, you could avoid it by switching the steps - you need to first set the size of the window object and then set its Url.
oWnd = $find(
"<%= RadWindow1.ClientID %>"
All the best,
the Telerik team