More editing control over membership site emails and pages

It would be great if we could have more control over the system-generated emails and pages of membership sites. Below are some examples...

• Editing logo attributes such as alt text and title for the email; "logo" appears in gmail preview text and there's no way to get rid of it!
• Change the design and add elements to membership site system emails
• Change the design and add/remove elements to membership site system pages.