Here are my thoughts, for what they are worth (not more than a couple of cents ...
)
#1 - if the result is cheese that tastes good, you are doing it correctly.
#2 - my experience with pasteurized, homogenized (P&H) milk is that the curds will very often shatter. Still can make good cheese (see #1 above).
#3 - my experience with the flocc method is that it gives not-very-clear results when using P&H milk. No matter how much or little rennet I use, I seem to get some sort of flocculation in less than five minutes, even though the curd is clearly not ready until the time that would be expected if the flocc happened at 10-15 minutes (or longer, if I go really low on the rennet). I've tried to wait until there is more than just resistance, until it is really impossible to make the bowl move ... that comes closer to the expected times, but is rather a subjective and inexact determination.
#4 - if you get your hands on raw milk, or even low-temp-pasteurized, un-homogenized milk, your world will change. Suddenly the flocc method works as expected--a very clear and distinct change in movement of the bowl at about the 10-15 minute mark, and curds are firm and not inclined to shatter.
#5 - I've read recipes that call for the CaCl at the very beginning, and recipes that call for it after fermentation and five minutes before adding rennet. I have tried both ... and can't say that I can tell the difference.
I don't know if others' experience with #3 or #5 is the same as mine, but I've certainly heard many people echoing #2 and #4. I've resigned myself to less-than-perfect curd with the P&H, and relying more on the recipe time and a clean break than on flocc testing, whenever using the milk that is normally available to me. Since nearly all of my efforts have met #1, at least for my unsophisticated palate, I have decided not to worry about it!