Tabbing to move around and space to interact are firm accessibility requirements. They should never be overridden, lest we get bombarded by many many legitimate accessibility complaints.
Sending a blank email is a legitimate thing too- many mailing lists require an email with unsubscribe in the title and no body content.
As others have said, this is the first time we’re hearing this. It’s going to be much easier for you to adjust to web conventions than for the internet at large to make allowances for you.