You are asking some strange questions for sure. But here are my answers:

1. Is it safe to assume that a metal spoon of some sort is used to measure and/or administer the Turpentine? If so, how do you clean or wash the spoon afterwards? Just rinse it in the sink with soap and water? Is it safe to rinse turpentine down the sink?

What's metal spoons got to do with taking turps? I've been taking pure gum turpentine using a metal teaspoon for 5 to 6 years now. It is quite a remarkable blood purifier i.e. it will kill bacteria, mycoplasma, mycobacteria, viruses, fungus, yeast and parasites. From all the research that I've read, it also does not destroy good gut bacteria. The Merck Manual(The doctor's Bible) banned turpentine in 1999, saying that if you got turps in your lungs it would cause great problems. Hey, if you put water in your lungs then you are going to have some major problems. Is water therefore a poison? Turpentine was used by the Egyptians and the Greeks both externally and internally. In the 1899 Merck Manual(find it online) a quick search on turpentine revealed that turpentine was used internaly for serious blood diseases like tuberculosis, gonorrea, syphilis and leprosy -- just to mention a few. Good enough? It has been used internally for thousands of years as a kind of cure all which is highly effective against bloodborne pathogens. I've also been using turpentine regularly for many years -- it cured alot of my problems in the intestines and in my blood -- and, apart from the occasional Herx reaction,  I've never once had a problem with taking it.   

2. Do you open the windows in the room in which you are using the Turpentine, to avoid any turpentine vapours?

What?  Just take one teaspoon of turpentine a day. Start with half a teaspoon and work up to one teaspoon. Make sure that the turpentine you use pure gum turpentine from the pine tree. Check that there are no additives like Xylene or Toluene in the turps. If you do that you will be fine. 

3. If you happen to spill a drop or two, do you clean the turpentine with a paper towel? Cotton/Cloth towel? How do you dispose of (or clean) either of those 2 types of towels (or anything else you may have used to clean up any spills) after it has turpentine on it? Is the towel considered "hazardous waste" and needs to be disposed of accordingly?

Oh my God!! You really do have an amazing amount of fear about using turpentine as a supplement!! Get rid of that fear or you will never be able to use it properly!! That means you should research turpentine for yourself to see how amazing it is. Start your own research here. 

4. Do you store your bottle/can of turpentine in a special location? Do you store it indoors or outdoors?

Usually bought in metal or glass containers. I store it in a cupboard away from the kids. That's fine.

5. Are there any other safety precautions you use when using Turpentine that I may not have mentioned above?

It's inflammable(so is whisky, vodka and brandy). I've found turpentine very easy to supplement. You can supplement one teaspoon of turpentine per day together with water or castor oil or milk or coconut oil or blackstrap molasses or sugar. Many ways to supplement turpentine.

6. Lastly ... has anyone from Canada (Ontario) been able to find or import the Diamond G brand of Gum Spirits of Turpentine? Apparently they can't ship their product across the border and I was just wondering what brand Canadians have used, whether it be Diamond G brand or another brand.

You don't have to use the best gum turpentine -- like Diamond G. I can't buy turpentine where I'm living in the Philippines so I just use pine oil(as essential oil) made from Pinus sylvestris(Scot's pine). I get my pine essential oil from ebay. You cannot ship turpentine to Canada from the US because its inflammable, but essential oils like pine oil will ship to Canada. Pine oil is the same as Turpentine. My pine essential oil is triple distilled which means that it is very pure and quite strong. I'm happy enough with that and I use it internally on a regular basis. And unlike you, I have no fear at all about using turpentine internally. I trust it completely.