I don't think the awarding of acres and scientists is appropriate because on a kdwide scale that could be unbalancing to some extent, also any rewards should not be awarded if/when the kingdom is at war but should instead be awarded at the end of war.
But other than that I see no real issues with this, the occasional random food gc or runes isn't anything particularly gamebreaking. Depending on how you implement multiple referrals I'm not sure that's a great idea, it's potentially open to abuse if it's just scaling the suggested bonuses.