Responses
The kingdom is poor and can't financially support him is the issue. They're also preparing for war and don't have enough money so giving away monetary rewards wouldn't do them any good at the moment. There's also the chance that the king doesn't know of Raymond's debt, since the creditors aren't actively pursuing the debt (because Rose finds Raymond intriguing)
From a leadership standpoint, why wouldn't the king support Raymond? Like I get that politically it would look like her supports him as a potential future ruler, but for a person who has done so much for the country and to still leave them in debt and not help him to continue to solve the issues of the Bay Region makes no sense. You can support him in ways without making it seem like he is a future kind prospect.