When you lower the turbo ratios and when you lower the turbo power limits, you sometimes have to reduce your undervolt settings. Why are you running your high performance CPU so slow? Intel CPUs can run reliably up to 100°C. It is OK for a CPU to thermal throttle at its Intel rated maximum temperature.
If you want a slow CPU, try reducing the cache offset to -100 mV and reduce the core undervolt to -125 mV. If your computer is stable for a few days at these settings, then you can try increasing the cache undervolt a little and you can increase the core undervolt. Change the cache offset in steps of 10 mV and the core in steps of -25 mV. A blue screen while undervolting is almost always a sign of not enough voltage. You should never be seeing a blue screen.
Have you ever cleaned out your laptop and replaced the thermal paste? That might be the real problem.