Hello,
1. You can setup a script on your page that requires a visitor agree to a license agreement before the Add to Cart button is clickable. We don't support doing so, but it's definitely something that can be done, and has been done with our cart.
Here's an example, one of our merchants has this setup:
http://commoncraft.com/store
2. You can place a test order by either temporarily setting your product price to zero or creating a 100% off discount code and running through a free checkout.