re: your first question, the hand doesn't jump in one day increments on the genuine, so it's not impossible for the power reserve to be at 6.5 days on the genuine -- i just think people like the fact that if you were to keep the watch on a winder (as many people do for automatics), it would read fully charged at 7 days.
the reality is no one is going to look at your watch and say "hmmmm....charged to 6.5 days, huh?" that must be a fake
re: your second question, yes it is an easy fix (just nudge the hand to 7)
hope this helps
deltatahoe