The form for Direct Pay on the checkout page is on lines 429-1661. You can add in a php comment around this area to disable it. You will also need to comment out the code that is on lines 1672-1708.
To comment out the lines you can select these areas of code and on the left in DW you should have a comment control that you can use to apply the comment. With the code selected click on the comment icon and choose to apply the php style comments. You will need to do this for the form as well as the spry validations that are on the page after the form.
I'm including an updated version of the checkout page with these changes applied for you. As for the email message do you mean to say that you cannot get the email at the admin address regardless or only when you use the email address as the cc in the globals file to get a copy of the receipt. If your admin email address does not get the regular receipt then they will probably not get the copy of the receipt. As a test make sure that you have a registered user with the admin email address then run a test transaction. Please post back with as much detail as you can.