Ok, question first! Hmmm... I'd say they're definitely mostlly in-character. More importantly, any deviation has a /reason/ and comes as a natural progression/consequence of altered circumstances as well dynamics between people.
Like, the core aspects of their personalities are still there, but they're wheigted differently? Does that make sense. I mean, Ace for example is still protective of his brother to the point of a complex, and can still get irritated to the point where he'd like to hit Luffy over the head. But due to Luffy's changes the dynamic between them changed (for example Luffy being stronger than Ace alters the "weak, crybaby btother that needs to be protected" aspect of their relationship).

Which... is a very convoluted way to say that any changes to their characterisation I witnessed so far -as far as they exist in the first place- are fine and don't worry, you're doing a good job. :)

As for the rest... I liked this chapter a lot! :D You handled your "resources" (meaning, the canon aspects reasonably available to you at this point in the story) very well to resolve a few things and to interesting results at that, that will certainly bring forth their own interesting little changes later on. Yep, I like this, definitely.

Thanks for the chapter!
Another another timeline error. This was all happening after the world noble and the fire and Sabo "dying", yet is this first time Sabo meets Garp? In Canon, Garp actually met Sabo, adopted him with fists of love and everything. Heck, he is the reason why the 3 moved out of Dadan's place and built themselves their treehouse base. Speaking of which, before all that trouble in Goa, they had been living together for quite some time, yet in the previous chapter, you wrote Luffy and Ace living at Dadan's and Sabo in a hideout in the forest.
Other than that, no misses.

Qotd: they are mostly perfectly in character! The only ooc thing I notice in Luffy, is that he is keeping the time travel secret. Canon Luffy is terrible at keeping secrets, would not think of the consequences of telling them, would probably not consider it important enough to warrant secrecy, and even if he did, he wouldn't keep it from his Nakama or family.

I’d say your depiction of the characters are splendid. One thing I especially like is that you’re luffy is not some huge cry baby. For some reason a lot of authors like to make luffy out to be someone who needs to be coddled and cries a bunch when really luffy only needs minutes to release his emotions and then he’s completely back to normal. I also really liked that you made nami not addicted to money since she hasn’t had to have hoarded it for a decade in this timeline, I’m excited for the other changes to her character and can’t wait for the next update. Stay safe

can you please stop with the fucking cliffhanger ? it's annoying as shit ...

I really like your story. And I totally agree that the pacing of the story is perfect. To your question, I think that with the exception of Nami and the later characters (I don't know until what arch you want to include the crew members) should stay as much in character as possible:)

First ,the pacing is really good ,I’m not overwhelmed by anything you wrote nor am I wishing it to be faster . Second ,what you wrote was really good ,give yourself more credit . If that does not make Nami join him ,then all hope is lost ,haha ,Luffy now has 8 years to get back close to his original strength ,please keep writing , because I don’t wanna stop reading.

You need to give yourself more credit ,the whole chapter and the fight scenes ,Sabo and Ace vs fishmen and Luffy vs arlong were very well written ,the duration of the fights was pretty spot on ,they weren’t too short and they did not drag out and become tedious ,the objective was achieved and Nami does not suffer the same fate ,love it ,so good but what happens next ?.

Your pacing is quite nice, but I suggest a time skip soon otherwise I fear you will lose motivation during the whole East blue arc as have so many other one piece writers before you. Also change some plot points to help keep it interesting for yourself. Not just time wise such as Luffy saving Nami earlier this time, but new enemies for this story for you to create. Don’t be afraid to deviate from the original story as this one is yours. And above all don’t apologize for the changes you make to the story as this is your fanfic not the reader’s. We should be coming to read a great story from your point of view and not to criticize every little thing you change from the original story. If we don’t like it we don’t have to read it. Anyone who does continue to read your story and criticize you is simply trying to troll you into quitting so just ignore them. Especially by the time you get to logue town if someone is still reading and criticizing ignore them.
Kind regards and hope for the future of this story.

Pacing is fine.

Good stuff ,Bellemere was meant to die, it’s an important part of Nami’s story ,although saying that Sabo was meant to disappear ,that was a big part of Luffy’s story but seems to work out well how you did it . and Nami has her hero early ,it’s gonna be tough for ASL to win this fight I would imagine ,best of luck to em.

Thank you! Thank for writing this story and for writing it well! There are so very few good one piece fanfic out there and almost all of them end up in 3 categories. A) Girly shonen-AI fantasy. I was so glad to see you wrote the 3 brothers interactions like in the manga, true brotherly rough and tumble love, will full confidence in each other. B) Antsy teenage bloody dark fantasy. Pretty much avoided, even with this fights, it felt more like when they killed them, it was a spur of the moment necessity, and not gory for the sake of coolness. Hopefully as they grow stronger it becomes less necessary. And C) Horny teenage harem fantasy, so I was super relieved with your A/N at the beginning of the chapter. One Piece definitely doesn't need romance.
For the longest time I mostly had to content myself with Black Victor Cachat's and a couple of other stories sprinkled here and there so I'm super excited to see how this story develops. I Have a few interesting developments and power-ups for Luffy regarding his awakening for my own story which I'm probably never going to write if you are interested, so you don't have to go with the tired old cliche of having him learn rokushiki, which is apparently all that most author can imagine lol.
P.S. I wasnt really paying attention because the story had me pretty trapped, but I didn't notice very many grammar mistakes, so great job on that too!

I’m really enjoying how you wrote the last couple of chapters ,I like the fact that Ace and Luffy told who their fathers were because now Ace has at least one person who can identify with him, their bond will be even stronger for it.

I suggest you reread canon -

Seastone doesnt revert a devil fruit user body back to normal -
The canon Arlong fight should be more than enough proof of that, in which a submerged Luffy neck was stretched for hundreds of meters for him to receive a mouth to mouth.

Contact with Seastone only weakens the Devil Fruit user and prevents them in the case of Logia to become intangible and thats it.

Defibrillator really? the general technological standard we see in one piece pretty much mirrors the 18-19 century ... with certain outliers like vegapunk, Usopp Franky, etc but those are the exceptions. So far we have yet to see a battery that is not a dial one piece, therefore, it is more than just doubtful a defibrillator would exist or be accessible by the masses like Dr. Nako

And Luffy getting over feeling guilty why?
It is not like he didnt know what would happen or couldnt have been earlier in Cocoyashi like months earlier ... so why exactly with him really being at fault, that Bellmere is dead does he get to shed his guilt this easily?

His inaction, not caring about his crew-members until they are part of this crew led to this very situation ... In a sense quite OOC by the way. Luffy expected from his crew members to care for what he cares and there was the unspoken promise he would reciprocate the sentiment ... something he here clearly failed to do.
Then going ahead and lying to Nami (he dreamt what would happen) instead of telling her the truth to keep the possibility alive she might join her "hero" is underhanded ... not something you would expect from Luffy ... and is certainly not a good start for any relation starting it by a lie even if it is only by omission.

So yeah - not a fan of this chapter either ... and at this point, it is doubtful future chapters will change that ...

Poor Luffy ,I hate it when he’s in pain ,but in these stories it is a necessary evil ,he is going to have to work like a Beast to make sure history does not repeat itself ,I’m excited to see where you take this story ,hopefully Luffy heals and grows with the passage of time.I also would like Shanks to meet the man that made Luffy this way.

Great start ,my interest was obtained immediately, can’t wait to read on.