(1) The four “shop” buildings are more like support buildings for each race. Their cost is low and their hp is low. What I don’t understand is why their build time is so high - 60 seconds? To me, it would make sense to reduce their build time to 55 seconds. This would probably slightly benefit ORC and UD race, but overall will keep things balanced.
(2) In one of the threads, wc3tutor mentioned that the backpack upgrade can be moved to the shop. The reason is that the townhall is used to have continuous production of peasants in the early game.
It is a nice idea that can be implemented. There is a free icon to place it for each race in the top right corner. It would be cool, if it could become an instantaneous upgrade, something like “get backpacks for your units”! Going tavern heroes first would be fun ))