the RadControls included in the Sitefinity distribution are licensed and restricted for use only on Sitefinity projects.
If you want to use RadControls for other projects, you need to purchase a separate license.
As Robert mentioned in the post below, there is a known issue with RadControls lifecycle used on Sitefinity pages that we are currently working to resolve. We expect to have a solution to that problem and distribute it it in a hotfix by the middle of March.
You can start your evaluation of Sitefinity with that in mind.
I hope that helped!
the Telerik team