1) The barrel on mine looks just like Justice06RR's that is in his picture he posted, except mine is minus the front sight. Why does the barrel have those separations in it, like it has been spliced together, what's the purpose of that?
2) I'm 6' 2", and even with the 6 position stock, when I got my rifle, it is still too short for me. What, if anything, can remedy that?
1) Those are M203 cuts. They are there as a mounting point for an M203 launcher; not necessarily applicable to civilian shooters, but some like it for the novelty/looks.
2) You can add a recoil pad that will add a little LOP, but other than that you would have to change stocks. You can go to a full A2 style stock, but IMO they take away from the aesthetics of the "carbine".