I just started recently, am on my first character who is a throwing/2H character, and I really enjoy the throwing (so much that I often wade in with a pack of only heavy throwing axes), and even though I've become quite accurate with them, the wpf limit means I have to carry light armour and so die rather quickly (specially to archers), and any enemy with shield or heavy armour make my shots useless.
I definitely think that a small increase in stack, and a small decrease to the wpf requirements is needed. In addition I'd like to see a bit more given to heirlooming, as I plan to heirloom a throwing item, but at the moment, I can't see it being worth it. Perhaps a 1 point increase of missile speed on 1st and third heirloom (second has speed increase)