Two Pbs: Sporadic Loss of Power and Thermostat stuck open

[Das86TurboII]

I have a 2012 335i xDrive M Sport. Has anyone experienced either of the following two problems? And if so, what was the solution?
Problem #1: Sporadically the motor will loose power. I've experienced this while driving at high way speeds. The change is subtle. When it happens the cooling fan turns on despite the temps being below operating temps ~160-170 (see pb #2) I need to increase the throttle input to pass etc over what I would normally would have to. I'm not hearing or feeling the turbos kick in. If I stop the car, turn off the engine and immediately restart it, the engine performs normally. Its almost as though the engine is going into limp mode. No codes are being thrown. Max speed, ~65-70.
Problem #2. I'm getting a "Thermostat stuck open error". The Thermostat is brand new. In cold weather (below 30 deg) the Thermostat may not move off the 160 (min temp graduation) mark. During summer months the needle moves to the normal operating temp point. So the thermostat is working in that it recognizes a set point and open/closes to try and reach normal operating temp. Shortly after purchasing the car, I installed a SCF high capacity radiator thinking I might track the car. I decided not to track it. Left the radiator in thinking it would be good to have the extra cooling. Does anyone have experience with the CSF upgrade? Does your car reach normal operating temps in cold weather? Is there a setting I can adjust programmatically? As we all know replacing the thermostat on these cars is a PITA. Is there a way to test the thermostat? Wondering if a bad lead could be causing it to fail open?
Could the two problems be related?
Car has 78K milkes