Hide the confirm email and confirm password fields from the Paid Memberships Pro checkout page.

gistfile1.php

/*
	Don't show confirm password or email fields on the checkout page.
	
	Add this code to your active theme's functions.php or a custom plugin.
*/
add_filter("pmpro_checkout_confirm_password", "__return_false");
add_filter("pmpro_checkout_confirm_email", "__return_false");