I should point out that there is no such thing as a peasants caste in Rokarism - the peasants are in the same caste as yeomans and townsfolk. Although such people would still be prohibited from bearing knightly weapons (as well as the nobility), there are still plenty of weapons they can and should be allowed to handle.
In my opinion, peasants have reduced legal rights because they have not assumed the full title and responsibilities of a Malkioni citizen. They thus have the same legal status as idiots and children - they are subject to the direction of others but have an easier time of obtaining Solace than everybody else. So what looks bad from the Loskalmi point of view is actually good for their own benefit.
I don't have any objection to a Saint of Thieves as such, what I like to avoid is a consequent formation of a Thieves Guild in every Malkioni city of note (I won't deny that there is a thieves guild in at least one Malkioni city, my preference is for it to be an exceptional social innovation - perhaps an uneasy coalition of several different thief saints).
Rather than construct a thief saint as a perfect thief that is never detected, I think it would be better to have the thief saint as covering a specific crime and that he has to follow specific caste and occupation taboos when performing his work.
For example, Rokari are supposed to be meek and humble when dealing with their caste superiors. How do you think a Rokari peasant thief will behave when mugging from a lord? And if he falls from those standards, how will he do penance afterwards?
So here are some of my suggested thief saints:
The Savonarolans - these thieves are notorious for stealing sinful (and only sinful) possessions. In worshipping their saint, they throw the possessions onto a large bonfire. The wealthy hate them but they receive spiritual support from some austere factions in the church.
The heirs of Ziklag - Ziklag was a famous knight who was unlawfully deprived of his fief by the Doge of Nolos after Old Seshnela was sunk beneath the waves. New Nolos was founded on top of Ziklag's castle. Ziklag's heirs continue to exercise their ancient rights, mainly by demanding protection money from the various merchants of Noloswal.
The Waertagi Ambassadors - when the God Learners exterminated the Waertagi, some embassies went underwater. From there they seek to control the port of their local city in preparation for the Waertagi return and to burn down the temple of Dormal.
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