I think this are fantastic ideas. I would suggest to have the idea groups permanently increase the loyalty of certain estates to a new resting point. This would get you into the "bonus range" more often, speeding up loyality recovery and slowing decay. I think there are several ideas were a little buff would fit. e.g. (meant as additive bonuses to ideas)
- Innovative / Resilient State: +5 loyalty to all estates (one of the weakest individual ideas in the game so far)
- Religious / Church Attendance Duty: +5 clergy loyalty (Religious is quite strong already)
- Aristocratic / Noble Resilience: +5 nobility loyalty
- Plutocratic / Free Subjects: +5 burghers loyalty