Yes direct payments and payments pro is the same... they keep changing what they call things.
It looks like they just updated the name of Express Checkout to Paypal Checkout as well. I found this on the site:
"PayPal Checkout is the new name for PayPal Express Checkout and includes some new features. First, PayPal Checkout uses a different integration method that can intelligently present relevant payment types to your shoppers based on what we know about them. We can also update buttons, payment methods, and the checkout experience automatically, with no additional work on your end.
Second, PayPal Checkout comes with new features such as Smart Payment Buttons, newly supported payment methods like Venmo, and shopper insights."
The NVP/SOAP implementation that eCart uses is deprecated, but Paypal doesn't ever stop supporting customers that use it. There are just too many people on those systems that they would never want to cut off. When I do eCart 6 I'll update it to use the latest and greatest, or at least support it, but for now I wouldn't lose any sleep about using the deprecated version. I use it on the webasisst site and other sites I own and manage and I really don't anticipate paypal would ever actually turn it off. They just don't want new customers integrating it and don't put any resources toward making updates anymore.