Once the PayPal Subscription Profile is established, it is attached to a specific PayPal Account. Even if you change your email address the subscriptions will still bill.
If you setup your Subscription Payment Button to a specific email address and not your Merchant ID or a Hosted Button with your Merchant ID, then your buyers will have issues with creating new subscription payments if you change your email address.
Here's how to edit a saved button:
Log in to your PayPal account.
Click Tools near the top of the page
Click the PayPal Buttons tile.
Click View your saved buttons in the top right corner.
Click Action near the button you would like to edit.
Click Edit Button.
Verify under Merchant account IDs "use my secure merchant account ID" is selected
Change your button information, and then click Save Changes.
Click Select Code, and then copy and paste the new HTML button code into your website’s code.
Here is information on managing existing subscriptions: