Minor thing. Duke Oren is referred to as 'his highness' but the appropriate term to use for dukes in English would be 'his grace.' As with everything related to nobility, terms of address are needlessly stratified. I'd recommend referencing this wikipedia article when you're not sure...
I mean if we're going by real world history what they need most are the printing press (dissemination of ideas, obv), coffee(so that philosophical discussion will be under the effect of a stimulant rather than a depressant like alcohol), guns(require comparatively short training time so peasants...