Appreciate your feedback!
Twigging has and will always be an issue. Making twig decay faster will just hurt new players, often who think twig is wood. It's 2 weeks because that's half way through a wipe cycle and gives players plenty of time to be active before all of their hard work is removed.
There's some issues with our inactive purge system that once fixed will clean up a lot more structures. I'll be working on it on the side as I push new features very soon.