Thank you for your feedback!
Straight to the questions:
1. There is no built-in way to automatically resize the summary. You need to calculate the start and the end date of the summary task each time you manipulate the source collection. We attached a sample project that shows how to achieve this behavior. We will consider including such kind of behavior for the Q1 2013.
2. We have this feature already in our schedule, but it will be not finished for Q3 this year.
I hope this helps you further.
the Telerik team