That is honestly a very good idea.Good stuff @cyresdog. I like all of it. There is one minor tweak that I would suggest to your ideas though.
Perhaps that messenger could be a companion, and the higher that selected companion's charm is - the more likely it will be that your terms will be agreed upon.
But the less honour the Lord you send it to has the more likely it is that your Messenger gets captured. There should be also a downside of sending someone instead of just no risk. Same goes for Quests in my oppinion. Whenever there is a Bandit Hideout quest i mostly send a companion because they have a 100% chance