You never deal with Dish if you only sub to Sky Angel. Similarly, you never deal with Dish if you only want to subscribe to NPS. I may test this later. I have a 942 for my father that was never activated and is still sitting in storage (don't ask...

) I may go dig it out, connect it up, call NPS and see what happens. If all is as it should be, the fact that it's never been used for an Echostar sub shouldn't matter.
As for the multiple receiver fee, that's an NPS issue and has zero to do with Dish. Again, if all is as it should be, they will never interact beyond the level of uplink and sat-space provider. As has been said, if NPS is looking at Dish's customer database, that blows the entire premise of an unrelated third party out of the water.
If the legislation passes and Dish gets the ability back to offer DNS, I don't see them turning off NPS. NPS may choose to discontinue the service due to lack of profitability but there's all SORTS of problems with E* pulling the plug. I doubt they'd be that stupid anyway. If anything they'd wait until the lease was up and jack the lease rate through the roof.