lots of questions there

I will try and answer them! The reverse style is to try and imitate the way that the natural faces upstream, as the usual method of fishing dries is to cast and present them upstream. On a lake, this theory goes to pot, so whether it works or not it shouldnt make a difference.
Now the casting thing, I reckon you won't be able to tell the difference. This style does have its uses though, IMO it helps to sink the tippet, at least from the reverse emerger patterns I have used, and I think long, stiff tailed dries would be better accepted in to the mouth of a fish, especially something like a grayling if tied in reverse.
Hope this helps!