Hi MJ!!

I suggest using the whey to make your brine.  Whenever I've used water it kind-of results in a "washed out" flavor that I don't like as much.  (You can use water though if you like!)

I also use whey with salt in it to heat it for stretching (I don't use the microwave…I do the whey & salt on the stove top in a pot and use a large skimmer to lower it down into the hot whey/salt.  That way I can just pick up the skimmer rather than having it floating around freely in the water.)

For me, the batch – even if it's just 1 gallon – is too much to stretch at one time.  If I'm using a gallon I usually divide it up to about 3 pieces for heating/stretching.  That's easy for me to accommodate and then when I make it into a ball it's about the size I like. (Also a matter of personal taste…if you can handle more, you can.  If you want the smaller balls, make it smaller.)

As far as the amount of salt, I usually just do that to taste.  But, again, there are formulas for %brine that you can use if you want to be technical…I have those charts somewhere and if that would be helpful, I could look them up and post. 

If you're just wanting to get a "saturated brine" you can do that visually.  You stir salt into the liquid until it begins to separate and won't hold more salt.  What I mean is, you'll see the salt in the bottom of your container and no matter how much you stir, it just can't incorporate any more salt into solution.  The amount of salt you state above would likely give you close to a saturated brine if I remember correctly.