Will this work for courses/memberships/group coaching/physical products/application processes?

The CSS definitely works for courses, group coaching, and other information products like that, but there’s also no reason that it couldn’t work for physical products, masterminds, affiliate promotions, and other offerings. I will say that if you offer a membership, it’s likely you’ll want to make your initial offer for six months of access or something like that and then continue them on with monthly payments.