Two things:
1. The statement "orgo is not that hard as a freshman" is completely useless because of how much it varies from school to school. My orgo class was about 80 people and the prof made a point to tell us he would only give out 5 A's maximum. There were also no + or - for that class, so if you weren't top 5 in the class, you get a B or lower. He also reserved the right to give out less A's if he felt (below 88% meant no A for you). From the sounds of it, orgo at Mich isn't too bad, but this certainly is not the case everywhere and at some schools (like mine) freshmen will struggle just to pass.
2. Skipping gen chem is only a good idea if either the class is not an 'easy A' or if you really are taking so many science courses that 8 extra credits won't significantly affect your GPA (I'd say 60+ science credits). Let's say OP took 60 credits, somehow managed to pull solid A's in everything other than biochem in which he gets 2 B's. Let's also assume he's at a typical school where each class is 4 credits. If you do the math, it would drop him from his 4.0 to a 3.86. A .14 drop in GPA is definitely not insignificant, and I would not consider 2 easy A's in a science course a wast of a year.
One last thing to keep in mind, different schools use different parameters when selecting their students. Some will place a huge amount of weight on the MCAT or a single GPA aspect, while some will highly value a well-rounded applicant. OP doesn't know what the med schools that he will eventually apply to will look at, so the little things like 8 chem credits worth of A's can end up making a difference, even if it is only a small one.
