>Possessed weapons vs rust dust?
There are animated armours that are specifically weak to this potion.
>*Some* gardening aspect.
That's possible, but not very likely, as I expect the player to go explore anyway.
>An unlockable material stash in your workshop
Probably won't happen, I have certain plans for the story that won't fit with this mechanic. But I do plan the "lives" mechanic instead.
>Golems/elementals!
In all likelyhood, there will be one golem, since I, too, don't enjoy large parties very much. But I haven't yet decided on the details.