I agree, the decay system needs some balancing.
Some structures just don't decay that easy. Every kind of stone building should last ingame years not days. I understand that the decay system is necessary to keep the servers clean, but huge things like fortified stone walls and castles should not decay that quick. I could imagine, that some players would like to build something like a chinese wall to seperate parts of the island.
As for tools: there should be different quality levels (primitive/stone, bronze/copper, iron/steel, vostaskus steel) with different decay rates. And usualy wooden parts get broken a lot easier than metal parts, therefore it should be possible to just renew the handle of a tool.
And for devices: the get broken way too quick. For example a fireplace. What part of a fireplace can brake? But on my server i can't even use a fireplace longer than one single load of fuel (5 hardwood billets) before it gets broken.
And we are on the same page with the food decay.. i already suggested that: Spoilage
And i made a collection of some suggestions, that would increase the realism of the game: More difficult struggle for survival