Basic question: which is the low heat setting on a broil-mate BBQ and which is high? Thick bars or thin bars?

What kind of brand of oven that you are using? There are two types where you can you can use your broiler.
*Low Broil: There are 2 broil elements. In low broil only the inner element is on.
*High Broil: There are 2 broil elements. In high broil both the inner and outer are on.

it should pull off the orifice or there may be a screw holding it on

Hi this may help.
http://content.charbroil.com/content/Char-Broil/Knowledge/463441913%20English.pdf
I Hope it helps.

Since your grill uses a V - bar flame tamer over the burner, I wouldn't recommend using Lava Rocks. As there is no grate to set them on above the burner. Putting them directly over the V-bar flame tamer, won't allow the burner to heat evenly and you'll have hot and cold spots throughout the cooking surface.

Hope this answers you question.

The hiss is from the reg when the pressure equalizes on both sides of the diaphram with the pressure coming out of the breather hole . So check the reg .

You do not want to recharge a/c on high side, look at both a/c hoses coming from a/c compr, there will be a thick one and a thin one, the thin one is high side, and the thick one is low side, recharge a/c at thick hose port.

take it back

Your frustration is common because the new tanks all have a safety feature built into them which is a pain in the you know what. Unscrew the tank to reset the safety valve and then screw it in again. That should result in the valve being in the open position and working for you.

wood chips in the fire box. very low heat. around 200 degree.
maek sure the wood chip is wet and produce smoke. you need to monitor this through out the process.
briskette in the grill side without any heat. depends on the sixe and the thnikness of the meat, you need approximately 12-20 hours before meat become tender.
here are few web site you can get some information
http://www.smoker-cooking.com/howtosmokeabrisket.html
http://bbq.about.com/cs/brisket/a/aa111503a.htm
http://www.wyntk.us/food/smoking-brisket.shtml
http://www.bbq-fyi.com/how-to-smoke-brisket.html