Hi there! There is no minimum spend requirement to take advantage of the AWS credits. They are promotional credits and will eventually expire; see Amazon's terms: https://aws.amazon.com/awscredits/.
Your business doesn't need to be incorporated to apply. Sole props are welcome! It's worth noting that the personal liability changes, though: the individual behind the sole prop will be personally responsible for charges on their account.
(Amber from Stripe here. For folks following along, we're talking about the "Additional Benefits" section on the page.)
Anything that says "cash back" is automatically applied to your card spending and for both new and existing customers. For everything else, we'll give you a discount code to type into the partner's site directly!
Right now, you pay through a linked bank account. We are planning to let you pay from your balance in the future, though. (Most of our early users preferred the former.)