Maybe the addition of Stamina? I'm sorta posting this blindly, only have reading a few posts, so bear with me. (or yell... either way works

)
maybe develop a sound mechanic to go along with the weight mechanic to address the issue of moving quietly with heavy armor. I have no idea how ahard that would be to set up, just an Idea.
(I played D&D for a while, and I ended up falling off a fort wall I was trying to climb due to my crossbow. idk how that came to be, but we stopped soon after that incident... Too many guards watched a rouge fall a good 50 yards after a sudden expletive. that left the other three to deal with them after being exposed. we had a bad DM...

) (that where my Ideas came from...)