We'd like to have a non-admin test a donation page. Can I just send them the test page and have them test this?
The donation form test page is an admin page, so in order to test the form, you would need to be logged in as an admin. Alternatively, you can send the front end (or live) URL of a donation form to a non-admin to test with. Note that this does require a real credit card transaction to be processed in the minimum amount set in your instance (typically $5) and later refunded by an administrator.