1): It is not an act of war to take unclaimed land. It is an act of war, however, to starve civilians. 2): Craft put the colony there. 3): They can grow their own food... They don't rely on imports. 4): If I were to sell it to you, maybe I should consider putting a ridiculous price on it. Rhun gives no response for now, other than to say they are considering selling it, but it is up to them.
To be honest, I don't even want that tiny part of the colony, it would be a nuisance to my infrastructure. However, the main reason I am stalling is because I do not like Muscovy's aggressive policies and threats.