Hello,
I am glad my little project interested you 👍. For now there is no way to remove bigger stones. There will be a pickaxe in the future probably, not sure yet.
Also the land will eventually have more shrubs and grass patches.
Boat is for a cosmetic purpose for now, Nico will arrive on it and will travel somewhere in the future 🤔.
No way to unequip the tool, as tools selection grows maybe I will think about unequiping it.
Good questions overall, sorry I don't have good answer for them as of yet 💚.