i like this.
A chance of getting access to some letters a bit like a torture report but instead less messages.
The target should always be the noble though, not the estate.
Make it work just like an assassination attempt but with less risk.
A chance of a fight breaking out, getting caught by guards etc.
I'd like to add the option to steal gold from a noble directly instead the treasury of a region.
This should be a bit more risky then the local treasuries.
The infil can first do some spying, check how much gold the noble has and then decide to go steal it or not.