Setting up each experience like an event registration page with a payment link sounds practical. I’ve done something similar before, and it worked out well, especially for handling donations directly through HubSpot payments.
As for the features you’re looking for, HubSpot does allow for coupon codes and automating confirmation emails, which can be super handy. For the waivers, you might need a bit of creativity, like sending it as a follow-up email or using a third-party tool integrated with HubSpot. Also, I’ve had good experiences with ATLOS for accepting crypto payments. It adds flexibility and keeps things simple. Just some thoughts from my side—hope they help