Thanks! I'm glad that you found this project and hope you will enjoy using it!
Here are some answers for you:
1. The Application class wraps the create_window and destroy_window calls to make them a little easier to work with.
with agk.Application(): pass # application code is here
is the same as:
try: create_window() pass # application code is here finally: destroy_window()
3) As far as I know, you can import any modules you like. (If I understand your question.)