Hi,
Thanks for your feedback.
Note that a guest user cannot subscribe to a product waitlist without an email address. It is mandatory.
I did some tests following your message, and I can see that I can subscribe to the waitlist after having emptied the email address if I'm logged in. That's indeed a problem. We're going to fix that.
The name is not mandatory and not much useful. It's only there to be included in the email notification.
If you want to see or change the waitlists, you can do so via the menu Customers->Waitlists in your backend.
The way the system was made, it allows you to enter another email address than the one you registered with for the waitlist notification. And it's not linked to your user account. But it could indeed make sense to have a link to the user, especially to remove the waitlists after the user is deleted. We'll add that on our todo list.