I've already talked about all the problems I have with 2E (as have a great many people, at great length), so now I want to talk about how the game could be fixed, and what could make it more appealing.
1. Revised Proficiency System. There needs to be more disparity between highly proficient characters and non-proficient characters...not just in some wall of text feats, but in the actual game numbers. Something you can see and feel at a glance. I've seen a lot of suggestions for 1/2 level plus -2/0/+1/+3/+5 or -3/0/+3/+6/+9 (the second one is what I'm currently using). Whatever the case, this needs less bloat and more differentiation between ranks.
2. Easier Readability. This is another big one. This game reads badly. It's wordy and bloated with everything referencing something else and just performing a single task or making a single character choice can require a lot of book-flipping. More than clarification, the book needs restructuring.
3. Less Bloat. This is systemic to the whole game. We don't need the same feat regurgitated for multiple classes, and we don't need to be rolling huge numbers for everything in the game, instead of just the things our characters are really good at.
4. Action System is Too Restrictive. There needs to be more things you can do with it, and there needs to be an action that combines move and manipulate (move half speed and draw a weapon, etc). Also, the Ready action is basically useless for casters, which feels really bad.
These are the four points that would prevent me from buying this game. I've already had to do a lot of houseruling just to make the game feel playable. Unless these things at minimum are fixed, I have no reason to invest in a game mired with severe deficiencies.
1-3 I'm in complete agreement with.
4 I haven't run into at all. The three action system so far has worked beautifully for us. That said adding some extra uses like a combined move/manipulate or tweaking the ready action wouldn't bother me to see changed if it helped make the game better for others.