How should a gas fireplace work?

I'll get right to the point.  How do I turn this OFF?

I can turn the manual valve all the way on the left, but that also kills the pilot light.  There should be an gas valve in line after that I can turn off via the wall switch, or the switch pictured in the lower right next to the igniter button, correct?  Are these typically wired in series?  I have tried all 4 combinations of the two switches and my fireplace isn't turning off.  How long is the delay between the right combination and the gas going off?

I usually turn the whole thing off anyway, I'm just prepping for an ice storm predicted tonight/tomorrow morning.  But realizing I can't turn it off might mean there is an issue with that valve, which is also a safety issue, right?  If I am reading correctly, it has a thermocouple in-line that is supposed to cause the valve to close if the pilot light is off/gas isn't igniting.

The thermocouple sends a signal to the gas valve to stay on if it senses the heat from the pilot.  If the pilot stays on, the thermocouple is working fine.

 I'm going to guess that you have a problem with the second knob from the left, which I think is supposed to be the thermostat, but if it is, its in an odd spot to sense room temperature.  Is there another thermostat somewhere?

Or does that knob just control the height of the flame, and its supposed to burn all the time, or not at all, based on the on/off switch?

That doesn't make sense.  So any time the pilot is on, the main gas supply is on?  There is definitely a way to have the pilot light on and the main gas supply off.

Second knob from the left is just LOW-HIGH (flow rate).  There is no thermostat.

I was editing the above when you posted.  I also re-read your original post more closely, and I think you may need a thermocouple.  That is what keeps the pilot on.  

The thing is a bit odd.  There appears to be a bbq lighter right under the pilot light as well.  I presume its designed to be shut off regularly, and easily re-lit.

Is there a knob on the actual gas valve?

I just took a look at mine.  Used it a couple days ago when we were without power to keep the house toasty.

The body of the gas valve, which is pretty chunky, has a few spade terminals with wires attached.  There is also a rudimentary wiring diagram on a sticker right on the valve body.  Mine has a toggle switch mounted right behind the safety screen, just an inch or two in front of the gas valve, that allows manual control on, off, and remote.  The remote setting allows control at a wall switch.

These things look like they've gotten much more sophisticated in the last 30 years. 
 

My parents have one. You control the gas with a knob, but you leave it all the way off unless you're using it. Theirs does not have a pilot light, we light it with a lighter. 

Does it have a switch? Or do you light it via the ol BBQ clicker?  
 

edit: your has a switch.

meaning it's electronic ignition. You don't work the valve, the computer does. Powered on, the system does everything, although a high temp sensor can automatically shut them off or turn on a fan. Turn it off, the stepper motor closes the valve ( actually think it just closes via spring without voltage.) 
 

There should be a ball valve for the gas line nearby.

In reply to pheller :

Necropost!