Well not sure my imput is of any help, as I too am new to this cheese too. My book said that the amount of white spore powder used was not critical, so I assume that in the right conditions, this mold spreads fast and effectively.
Have only used the powder so can't answer some of your questions.
I thought I might give your recipe a try and see what my results are. I have another recipe too. A "traditional" one according to the book, the one I posted here is apparently the "modern" one. Should try all three and see what the difference is.
Apparently the difference between Camembert and Brie, is the size of the wheel, thus the maturation time is different.
All I can add for now. Peeked at mine today, and the tops are now completely covered with a thick covering of mold. Tomorrow is day eight, when they will be wrapped and stored for another 2 weeks. Hopefully.