But feeling angry and leaning towards the path of evil just because of sh*tty lightsaber training is even worse than what has been done already. That sounds like a film catered towards the fans who just don't understand anything about story development, let alone character development. With anakin, there was already a good backstory as to why he acts like a victim and that's because he has terrible visions of the future which end up being true. Number 1 being his mothers death, which he tries to prevent but fails hard at. What made it even more sad was that he hadn't seen her since childhood and he promised he would come back, he came back too late. Secondly, he recovered from this and early in Episode 3, he has another vision in his sleep, this time it's Padme who gives birth who then dies straight after. That was the make or break and that broke him piece by piece. He even tells Padme what happened and she brushes it off as a bad dream, but he knows better and wants to prevent this. This time, his mental condition isn't great and he is vulnerable to manipulation and dark emotions which he just about controlled in Episode 2. What makes him different from other jedi's are that he's incredibly gullible, he is impatient in terms of his training and jedi status and has low self esteem.
Ya know, you could easily keep that plot and continue to add the plight of Qui-gon's death much further into Episode II or III. The heartache of Shimi or Padme's death does not have to be the only reason. It's not like I would have hinged all of Anakin's hatred and vengeance on some petty lack of lightsaber skills. The point I was making was that Qui-gon's death did not need to be so soon, and for two reasons: His character was one of the most intriguing, the Jedi Master who was all wise but too outlandish to be considered for the council. He was also the one responsible for finding Anakin, the most important character of the entire saga. Surely there was more to know of Qui-gon. Not only that, but Liam Neeson as an actor is fantastic, so this made his on-screen appeal even greater. Finally, because of the role he played in Episode I, it left a gaping hole in the character development for the trilogy as a whole. That didn't happen in the original trilogy. The ensemble cast from A New Hope made it to the end. Even Obi-wan survived in spirit. That didn't happen with Qui-gon in the prequels.