Edition Comparison Matrix provides detailed comparison of WPAS development plans.Editions Comparison Matrix
No, it does not. Development subscription plans are related to code generation not the functionality of your app.
When you cancel your subscription plan, you can not send your plugin design for code generation.
Login to your account. Under subscriptions heading, you will see your plan and a cancel link. Click on the cancel link to cancel your plan.
WPAS creates pot files automatically for every app. See details.