The default panel of the RadTabControl supports only explicit breaking, but you can use other panels like the WrapPanel and the default Tab panel to enable the automatic wrapping. I have attached an example on how to do this.
The MinWidth in this case works like it would in the columns of a grid - the does not in fact get smaller but is clipped by other items.
Also, instead of setting the MinWidth of an item in code, you can assign an ItemContainerStyle to the TabControl that will set the style of all items, there you can include:
<Setter Property="MinWidth" Value="150" />
Note that the ItemContainerStyle would work only when the items are databound.
The PanelChange will mean that unfortunately the selected row will not automatically move towards the content. We will address those issues in a coming upgrade of the TabControl.
Thank you for your feedback!
the Telerik team