The easiest way to llube a heater control cable is to disconnect the end at the heater and pull the control cable out CAREFULLY until the cable itself shows. Spray some lube down the cable housing and then on the solid portion of the control cable and reassemble and those should work nice and easy.
The engine shut off cable is somewhat harder to luibe mostly due to length. There is a spring against the end of the shut off cable so some resistence is normal, and is due to the spring. I would start by spraying the solid end of the cable control and work that back and forth a few times and see if that solves the problem. Sometimes you have to do the same as the heather cables and get some lube inside the housing. I leave the method up to you but once you see how they are put together, you see how to get lubricant inside of them.
In either case, spray lube such as WD40, or PB Blaster are suitable.
RL