The whole setup seems to me to allow the commoner to run away.
To a certain extent, yes, I agree.
If Nobles don't take action against that, those peasants will get ideas. You need to do your role as a Noble and enact some guidance.
And I agree with this, too.
However, the reality is that an advy who betrays a noble is almost guaranteed to get away with it, and with no consequences. Nobles are basically powerless to do anything about it, unless the advy happens to be in the same realm, and stupid enough to stay in the same realm.
IC betrayal has nothing to do with Trust Medals. What's told here is OOC. It shouldn't have reactions IC.
Oh, believe me, I've had plenty of IC interactions with advies. I've had advies walk off with items and never come back. Some have gone to other realms, some just disappeared, some just plain deleted or even got killed.
Plenty of very loyal adventurers out there anyway.
Yep. There are.
And if one does betray you, just make sure to make a good example out of him!
See above.