Not to argue but I don't think you have to level your exotics up again, that is only if you buy them off of a blueprint. As far as the "updated" exotics go it is my understanding that they will be substantially different weapons from their original designs and so leveling them again doesn't seem too inappropriate. The 200 cap on legendary marks is true but it is only a wallet cap, not a weekly cap. You can acquire as many as you want but you can only hold up to 200 at a time.