Gas dryer thermostat explanation.

I'm servicing a Kenmore gas dryer, model number 76912692. The non resettable thermal fuse opened and needs to be replaced. When I disassembled the dryer, there was a nice schematic (more of a block diagram) hiding under the control panel. According to the diagram, the series of devices in line with the heating circuit is as follows:

Then from there, it goes to the gas burner assembly.

I have two questions. If the thermal fuse is set at 186º what's the point of having a high limit switch at 205º?

The operating thermostat is a 4 terminal device. Two of the terminals make up the single pole switch. The other two terminals have a resistance of 7k ohms and from what I can figure out at the company's website that makes this device, it uses some sort of biasing to alter the cutoff point. Is this correct?

Thanks for your reply.