Amps and Preamps has standby, but should I turn them completely off?

Hi guys, I know there has been discussions of this and the overall consensus seems to be leaving the Solid State amps / preamps on (or standby). I have a Parasound A51 that runs pretty hot. The heat sinks are hot to touch after running them for 2 hours. Ever since I move them to the 2nd floor (gets hot in the summer), I worry that they'd run too hot so I turn them completely off (by switching off the surge protector) after each use. Note that standby mode doesn't solve the heat issue -- it still generates a significant amount of excess heat. 

My question is:
1. Does turning them off after each use shorten their life?
2. Does turning them off increase the probability of failure?
3. Does the excessive heat damage them in the long run by leaving them on?

I am not too worried about warm up time because I use them 2-3 times a week tops. I just don't want the excess heat on the 2nd floor since it's already much warmer than the 1st floor. 

Thanks!!