1.1. Customizing Foundation
The foundation store has been customized to add just about every ecommerce and content management feature under the sun. If you are asking the question "can I do ...." the answer is almost assuredly "Yes".
Note that customizing the foundation store will take some experience in web design and database operations. Perl experience is also helpful. Most of all it will take persistence and empowering yourself to make changes and watch what happens.
It is usually helpful to make a test store, perhaps just an unmodified copy of foundation, to test out your additions before you make them on your own store. That way you can try anything you want without the chance of causing problems on your own store.