Only if you have a WordPress.com Business account.
Nothing really, you will just not have access to theme updates or support. You can continue using the theme(s) for as long as you want or for as long as they work. It is completely up to you to purchase the theme or plan again (at a discounted price).
You are allowed to use our themes for personal or client sites as well as to install on multiple domains.
We can't guarantee our themes will work with any 3rd party plugns. There just too many to test. If there's a problem caused by incompatibility with a specific 3rd party plugin or hosting setup, we will do our best to assist you, but can’t guarantee a solution for any issues not directly related to the themes' code.
No, we do our best to showcase the themes as we'd see them being used. Keep in mind that if you are trying to decide between themes in the collection, you get access to the entire collection of themes with our one year plan.
Due to the nature of digital goods, all sales are final and we are not able to offer a refund. You’re buying our products "as is", so please make sure to check all features and requirements before making a purchase.