For the checkout form that posts the information to paypal, you have renamed a number of the form elements, this is not valid and will not work.
you cannot rename the form element in the paypal checkout form.
a number of the behaviors on this page use the Any Form Post trigger, this also wont work since the paypal form posts directly to paypal.
you will need to use the before page post trigger.
In reallity, when using paypal standard, the page that passes the transaction to paypal should not be used for storing the order or sending the email, you should set up an IPN page to do this.
paypal is not a real time gateway, there is no way of knowing when the order goes to paypal whether it was successful or not.
there are many threads in this forum that talk about paypal standard and IPN.
I recommend using Paypal Express instead.