For Korea, would it not be more correct to have the island of Jeju be made into a province?
I would give most of Korea a uniform 2-3 base tax and 3-4 manpower. Korea was not dirt poor, but it was never a center of trade or bustling commercial enterprise. Part of the reason why Korea was never really interfered with by the European Powers until Japan and Russia bashed heads over it is because it was never considered profitable enough to go there, even Christian Missionaries came rather late to the region. This didn't stop them from supporting armies and navies larger than most European countries had, however. Uniform good, with the possibility of improvement, but not bad.