You had me up to here, but then...If I were working on 6th edition years after 5.5e comes out, I'd remove the short rest mechanics
...you went the exact opposite direction I'd have gone. I'd have it that even a long rest doesn't necessarily get you back everything, in order to put long-term attrition back in as a consideration.and just simply have everyone have full hit points (hit points being treated as abstract wellness/toughness/luck and not as meat points) and fully replenished formerly short rest abilities at the start of every combat encounter.