Concerning the amount of yeast in this recipe, I was not aware of the differences in measurements between Active yeast and instant yeast. What...

I don't have as much experience as boulangere in this regard, but I've relied in the past on the advice given here: http://www.thefreshloaf.com/faqs/baking/yeast , which says to reduce by 20%. (That's a great resource, by the way.) Ultimately, how much less instant you use doesn't make that much difference, if you keep track of the rising process, and don't let the dough rise too much. With more instant yeast, the dough is likely to rise more quickly, I've found. The 50% rule is probably safer, in that the rise is more likely not to be so fast. A slower rise produces a better tasting bread, too. ;o)

A good rule of thumb when converting a measure of active dry yeast to instant yeast is to use half as much of the instant yeast. Conversely, if a recipe calls for instant and you only have active dry, use twice as much.