yes, universal email is easier to learn than eCart.
yes, you can add it to your already existing checkout pages as long as you are using local checkout.
you will add the universal email behavior to the confirm page.
for the to address, click the to button to go to the advanced to settings screen, you will need to enter 2 address:
1) click the lightning bolt icon and select the eCart_checkout_form_email address session variable to send a receipt to the customer
2) enter the store owners email address
for the body, click the DW Edit icon, in the body add an eCart Display manager, select the email friendly display type.