HTER/HETR and COLR/CLER as abbreviation for Heater and cooler. I believe it would be a good idea for it to, as you said, heat/cool the area around it. Can't you just make the area of application of heat bigger and it would work the same way though?
This has been suggested. Maybe a cool idea but suggesting it again is no good.
Life + Heatswitch. I see no point on adding tihs.
A lot of people don't know how to use life, nor what they would do. Often times when someone doesn't know what they're doing when handling life, this can get out of control. Just telling one person like @Thomasa is only going to decrease the population of people who don't know how to use life by one.
I had an idea like that HGNR, but citing :
"china-richway2:
Use ARAY instead. Also why do you want heat to pass INSL? Turn on Ambient Heat so that heat air will go through INSL. Also, when you want to melt METL/something, PSCN and NSCN will also be melted, just the same as Ambient Heat."
good idea though