Thank you for contacting us!
Unfortunately, Telerik RadRichTextBox currently does not support these two features. The implementation for supporting content controls like TextBox, CheckBox, ect. is already logged in our to-do list. The request about page/paragraph borders was not logged, but I logged it in the list.
I also think that such functionalities would be a nice enhancement to the control. I can assure you that we are doing our best to develop all enhancements to the control as soon as possible.
Please, let me know if you have other comments or questions.