This is probably one of the better and well thought out colony proposals for the game so far. I like the idea, but there'd have to be balancing, I like the idea of a cost for a colony in return for resources. And it reflects how colonies were money sinks for occupying/imperial powers with having to divert manpower to keep a local populace subservient etc. Not that this game needs excessive realism, but this is one of those situations where a possible mechanic just lines up nicely.
I also like the idea that this would add a new purpose for ships, considering how under-used they are in the war meta at the moment. So there's a lot of merit and potential for this proposal, I think.