At first sight I like it! The highest bars are maybe a bit too long, but the idea is sound.
I can see an exploit: infiltrators would tend to remain estate-less to escape prison faster, or could even drop their estate prior to attempting an infiltrator action only to retake it if they succeed. Would it be easy to differentiate between prison caused by a 'criminal action' and prison due to being captured in battle? I could see the low limits applying when captured in battle but a hard floor of 7 days when captured for a specific act.
