Ok, you are new here so we need to repeat some claims from the side which doesn't like Neymar currently too much.
Opinion from some of us is:
1. his first season at Barca was meh/average
2. 2014/15 was awesome, he was the 2nd best player in the world then
3. 2015/16, a good start when Messi didn't play, but then Neymar disappeared after a New year
-- in 2016 he was a crap in a CL knockout matches when we needed him the most
-- plus, he was invisible in the last 10-15 La liga rounds when we lost 10 points advantage over Real and when Messi and Suarez saved our asses in the end
4. 2016/17 for now is average again. Banging goals against Mickey mouse opponents in 7:0 and 5:1 trashings (Celtic, Leganes, Gijon), and quite poor whenever we played against a tougher team (Atletico) or when he needs to step up as a leader in the absence of Messi (Alaves, Gladbach)
So, you see, guys who dislike Neymar mostly dislike him because we think that he should have given way more to Barca than he did, based on his 100M transfer and based on his footballing skills.
Till now, he had one awesome season, and 2 meh seasons.
If this one will turn to be another average season, then we'll have a problem. We will have a guy with 1 season where he was a key factor out of his 4 seasons.
So, more or less, we don't think that he is not a world class player, but that his IQ stupidity, slowing down the game, unneeded tricks, partying too much are ruining his career and that he should have given way more than he gave to us (Barca).
Of course, skills wise he is good enough.
But as you said, IQ wise, decision's making, trying to please the crowd too often, trying tricks as if he is in Hollywood and not on a field etc...
Imo, THIS is a real/natural/default Neymar.
Neymar was similar as a teenager in Brasil.
This is a real Neymar, when he does too many tricks and when he slows down the game.
Neymar from 2014/15 and from autumn 2015 wasn't a natural Neymar.
Imo, he was playing against his natural instincts then when he played simpler, faster and more efficient.
Since he is getting older, and since his ego and fame are bigger and bigger, imo, it will be harder and harder for coaches to force him to kill his natural (playful) instincts and to play simpler and more efficient like in 2014/15.
You probably remember that we made tons of jokes on chat last season about Neymar: dribbling backwards again and wtf is he doing?
He played this way during the whole 2016 for Barca.
He played this way for Brasil at Olympics, but luckily they won a tournament, due to weak opponents.
He played this way for Brasilian NT in qualifiers lately.
He plays this way (slowing down the game, tons of tricks) for Barca in autumn of 2016 again.
(Some will say that he is assisting and scoring, but that is not the point.
The point is that he plays like "original/default" Neymar again when he tries too many tricks and slows down the game too much. And that is not good for Barca).
Ok, this was a match from a group phase of Olympics, and he played better later.
But I am posting this just to compare his current Barca's style of playing with his NT style of play and imo, they are the same.
It seems that it is Ney's new thing now. This is how he plays. He goes in the middle often, he enjoys to have the ball for 15-20 seconds in his feet, he slows down the game all the time, he dribbles past 3-4 opponents too often, he dives, he fights etc.
So, imo, this video resembles a lot to what Neymar did yesterday against Gladbach. So many wrong decisions, dribbling backwards, keeping the ball for 15 seconds, playing through the middle too often etc:
So, yes, you asked some good questions.
How to return Neymar from 2014/15?
Extremely hard question.
I am not sure whether he wants to play that way again at all :/