Kentico is a standard ASP.NET website so the short answer to your question is yes.

The longer answer is the main difference between the public facing site and the CMSDesk/CMSSiteManager is authentication and access. If someone can't authenticate the, they can't access the UI to make changes. There are hundreds if not thousands of physical ascx and aspx pages within the site that make up the CMSDesk/CMSSiteManager. You can typically use them on the public site by first familiarizing yourself with the file structure. Then understand how modules, webparts, form controls, etc are developed and used.

Once you have an idea on how those things work then you'll see you can simply take a few form controls (or custom ascx controls you've created), place them on an ascx control, add some properties and create a webpart/widget.

If you haven't already, I suggest creating a separate install of Kentico with the Corporate Site template. Fool around there and make some changes and see what happens. You'll be surprised how simple it really is.

Best of luck
Brenden