FFXIV's original reviews still sting to a lot of people who aren't final fantasy enthusiasts like us. Trust me when I say those reviews will keep ARR down in the three public's eye. If so much as one magazine lists ARR as an expansion pack it's all over. SE is going to have to try damn hard to separate ARR from the original release and I have my doubts about them being able to pull that off based on previous E3 presentations.
I don't agree with this at all. From what I've read and seen, most people either don't care about what the original game was like, don't know anything about it, or have realized that ARR is almost a completely new game. SE already has done an excellent job of separating ARR from the original release, by actually communicating with the playerbase, listening to them, and implementing things that they want. They've revamped almost the entire game, and have put out lots of content to satiate those wondering what it will be like. Each of those Live Letters is packed with info, concept art, in-game footage, descriptions, etc.
E3 is not a make or break moment for ARR in my opinion. The make or break time will be month 2 after the game launches. Will they have worked out most of the bugs? Will they be updating with new content fairly often? Will they keep us in the loop as to what's to come? If they can do that, I think it should do quite well.