Character wise Kishimoto claps.
Shikamaru
Gaara
Have better characterization than most Straw Hats.
Gaara really had a lot of development after his battle with Naruto, but there are many One Piece characters with similar development (e.g.: Buggy, Crocodile, Lucci), and some have even more fantastic journeys and buildups (Buggy's leap from East Blue "king" to Yonko, leading stronger pirates to the One Piece and "teaching" how to be a true pirate, was one of the best things that happened recently). Then, after his rescue arc, he was just brushed off, although he had a better run than most other characters.
Shikamaru is a well built character, I agree, but even him suffers from Naruto inconsistencies. For example, early in the chunins exams his plan to defeat Temari was basically the same that Naruto had to defeat Neji, yet only Shikamaru got promoted to chunin (btw, Naruto's early battles were full of great, overloooked, strategy). His initial plan against Kakuzu and Hidan was ridiculous, if Kakashi (and later Naruto) weren't there, Team 10 would be easily dead. His relationships with other characters and personality buildup (from lazy bum to an actual resposible leader) was great, but his intelligence is somewhat overrated.
Depends on whether you define world-building as quantity or quality. OP wins on quantity but quality is similar. I could nitpick all sorts of issues but instead I'll focus on my top 2 or 3.
1. Revolutionary Army is completely incompatible with JoyJoy. The idea underneath a revolution is that the history is UNWRITTEN and that your actions matter! There is no savior and if you want society to change then you must put in the work to change the minds of people around you and lead a rebellion that otherthrows the ruling class. In contrast the idea behind a chosen one and destiny (will of d, inherent will) is that the future IS written and your actions are futile if you're not the chosen one (e.g. Gol D. Roger). I think these two concepts are completely incompatible and if Oda wanted a story about a revolution then Sabo should have been the MC.
2. The world feels like a theme park or like Kingdom Hearts rather than a real world. a) Each island has a gimmick (eg. alice in wonderland WCI) but they feel isolated and don't feel like they're interconnected with each other. Events happen at 1 Island and the rest of the world is unchanged, similar to KH. b) Additionally, there is no consistently: magic is in the form of devil fruits and haki (ki, chakra) and then there is also advanced science. The characters include: gaints, gaint snail ships, moon people, gods, fishfolk, aristocracy, etc.
I could go on and point out other issues like retcons, e.g. Shanks and Buggy should already know the secret of One Piece or Shanks should have had haki to protect his arm but I think these issues are obvious.
As for comparing Doffy with Pain, I did that because both arcs are past the halfway point of each story. Pain wanted to save the world by causing everyone to feel pain. I disagree with his ideology but it was memorable. Meanwhile Doffy was reduced to an incompetant spoiled child. Both fights had dues ex power ups (sage mode, gear 4) and both were only useful for 1 fight before being replaced (jinchuriki/sage of six paths, future sight haki) and both had the gimmick of destroying the entire town/island. But the pain fight was more interesting because he had different bodies and doffy had a birdcage so even on the decline Naruto was at least as good or maybe even better than One Piece.
1. The "chosen one" trope is really a problem, specially recently, I agree, but I don't see incompatibilities between the revos and JoyBoy, I didn't really understand this part of your criticism. The real world revolutions never were simply "overthrowing the ruling class"... it was ALWAYS a new power rising (e.g.: Bourgeoisie vs. a weakened Absolutism in French Revolution, a new ruling class emerges). However, I see Luffy as an anarchist, while the revos seem to be more on the socialist side, so they may have some things in common (specially the enemies), but in the end they may not blend together. I don't think many things will change in EoS, Luffy (plus the revos probably) will just overthrow the current World Government (but there will still be kings, nobility, etc., maybe even the WG will continue to exist).
2. One Piece is an epic fantasy, so I really don't mind countries with themes or being heavily stereotyped. They have life on their own and their particular characteristics/issues. Naruto, on the other hand, looked totally generic outside of Konoha, everything looked centered around the Land of Fire. Well, One Piece is centered around the strawhats, but the events in each country DO have consequences for the world (e.g.: the Arabasta and Dressrosa incidents prompted the dissolution of the Shichibukai). About the "magic" and races "incosistency", I didn't really understand your concern. Different races has been appearing since East Blue and haki was appeared on the very first chapter... everyone who paid attention had it coming.
Shanks' lack of CoA in chapter #1 is really a inconsistency, I agree, but both him and Buggy were never hinted to be knowledgeable about the One Piece. We could assume that since they were Roger Pirates, but we knew since at least Arabasta (chapter #218) about the Rio Poneglyph and, so far, we knew that Shanks had no means of reading the poneglyphs. He could've a Laugh Tale's eternal pose, like in Stampede, but that wouldn't make sense considering Roger's last words (he would instruct only Shanks if he wanted him to be his successor).
Fair enough, although Pain's ideals were brought down by "talk no jutsu" in the end. Doffy wasn't incompetent, he just couldn't hold a candle to Luffy and was defeated. Gear 4th was useful against Cracker and Katakuri (in other words, by all of WCI) and for a part of Wano too. Pain's fight was indeed better, Dressrosa's final chapters were too dragged out and the birdcage was bs... but the ending was MUCH more satisfying, IMO. The arc comparison is sound though, they really encompass the same stage for each story, now I understand your point. I guess we just have a difference of opinion really.
I needed to go to spanish forums for discussions 
