Customise Express Check Out Screen using NVP/SOAP

Is it possible to customise the Express Checkout screen when calling it with API, e.g SetExpressCheckout, GetExpressCheckoutDetails, DoExpressCheckoutPayment

Ideally I would like to:

  1. Add my own image
  2. Remove the shipping details
  3. Restrict the payment options to PayPal Balance only
    3.1. Remove any card details
    3.2. Remove the ‘Link credit or debit card’ option
    3.3. Remove the ‘Pay in 4’ option
  4. Modify the ‘Cancel and return to ‘ link text

I have located express checkout variables but I am unable to use them in code, i.e. they have no effect. Having spent a few hours searching the web I am under the impression that customising the checkout experience is only possible with buttons created in the Paypal account