1) the gateway file looks correct, but also add the bindings in the test mode information.
2) I dont understand what you mean by this, please provide more details
3) on the success page, the store order summary and store order details are using a form post trigger, they should use before page load.
we will be releasing an update to eCart later today that will address a number of issues we have found, I suggest recreating the checkout page when the eCart update is available later today.