Thank you for your question.
We did not manage to reproduce this behavior. Can you give us more details on your scenario, or even better - send us a small sample project? We will be glad to review it and check where the problem is. You can attach it in a new support ticket.
As to the second question, we already have a RadRadioButtonElement but we don't have the control implemented yet. Most likely it will appear in the Q2 release later this year.
the Telerik team