On your first question if you set the option InheritParentDataSource to test A, and include it into a test B as Test as a Step, the test A will execute with the data binding entered for test B. IF you refer to the video I made for you and posted in my previous reply you'll see that test A executes with the data binding for test B.
On your second question, unfortunately dynamically binding data is not currently a built-in feature in Test Studio but you can review this article providing you solutions on how you can proceed.
All the best,
the Telerik team