1) NGE stands for "New Game Enhancement" and the reason why so many players (myself included) left the game after the NGE was released was the reduction and simplification of professions, simplification of gameplay mechanics, and Jedi becoming a starting profession overall reducing reduced depth and complexity of the game.
2) Short answer: Horrible. They generally do not listen to the community and on the rare occascion they did listen they screwed up the actual implementation
3) For me personally it boils down to the incredible crafting system and the huge open world that was fun to explore
4) See 3
5) The word "Opportunity" is actually a funny way to describe the initial Jedi implementation because although it was technically possible for every player to play a Jedi, people had to unlock a Force Sensitive Character Slot to do so and the inner workings of the unlock mechanics were unknown early on.
At some point it became clear that unlocking the FSCS was tied to mastering professions in the game and so the "Jedi Profession Grind" began. People would start to master each and every of the Game's 32 Profession in order to brute force unlock their slot. In my opinion this was the first phase of the destruction of the game because like Zombies people would no longer participate in any Guild activities but mindlessly Grind profession after profession (I did that too btw).
Finally if you didn't throw the towel during grind you would unlock the Force Sensitive Character Slot and would be able to create some kind of a baby Jedi Character on the same server that was not only very weak but also subject to Perma Death. That means if your character would get killed three times it would be gone for good.
