we've got previously request of this kind (to add some features to the pages), but since it is one of the cornerstones of the CMS, you can see how it's not really something that we can just add and see how it goes. I've written your requests down and we'll discuss this, but I cannot promise anything in this area.
We do not have any guidelines for extending pages in the way you'd like to do and for the moment being I am strongly suggesting you use the control approach.
The conclusion... we will think about it and discuss it, but no promises at this point.
Let me know if you need help with anything else.
the Telerik team