I don’t see a problem with someone publishing 5 great papers early in their career and nothing else. I mean what were the meaningful publications from Oppenheimer in his later years? Or Einstein? Publishing should be done when it matters, not when it’s needed for a salary increase.
I mean, the idea looks nice, but there will always be people trying to game the system.
But don't get me wrong – I still like your idea, I just think it would need some refining (as you yourself admit, ofc).
* As in, no research.