Unique items, weapons, and armor could be a slight solution to Mr.Wonderfuls issues, but I doubt it, hes a real downer on most ideas. If haven ever got large quest chains or actual difficult boss like monsters that could provide rarer components for gear or even completed items themselves then those who have been playing longer would still have an edge over new people who join and are just handed crafted armor. But in the end the edge their armor could provide would not matter if they had no skill.
Constitution could play a roll with stamina drain when doing labor and swimming still.
I have no issues with moving away from stat orientated combat to a more skill based orientated combat.