Nope. He left Doflamingo's family at 13. Ross found him when he was 6 month before turning 16.

Once again your definition of weak is freaking absurd. You're trying to measure strength relative to the strongest beings in the world of One Piece. Of course everyone else would be weak, that's why they are the strongest. It's not a binary division where you either strong and can compete with Yonko or you weak. There are levels to it. Weak is someone like Don Krieg. Doflamingo is in top 100 of the world strongest. That is not weak, far from it in fact.

Your point kind of contradictory to itself. He's not strong, but he's as strong as one of Yonko's officers? Doesn't that makes him extremely strong by the Paradise standards and even decent by New World's ones? If Luffy is weak for being defeated by a Yonko then I guess every pirate besides Yonko themselves are weak as well by your metric. What sort of measure even is that? If you lost to one of the four strongest pirates in the world you're instantly deemed as weak?

That address exactly zero points from my reply. How being good at gathering information will give you a sudden ability to procure maps that only denizens of an island use? If such maps even exist in the first place. I doubt much of cartographers would bother with city maps in One Piece. They're more needed for sea charts.

Island cities maps, if they exist at all, would be sold on islands themselves. Getting one before landing and extensively studying it would be impossible. It's like if I lived in London and wanted to buy a map of Tokyo. I wouldn't be able to find any physical map anywhere, only a digital one on the internet.

Yeah that stuff really exist. You can look it up. Hot spring one even got manga adaptation I think.

Then we finally done? That's a relief.

What is exhaustion exactly? Broadly speaking it is a depletion of 'energy' in muscles and accumulation of lactate. That 'energy' can be restored by food pills, true, but getting rid of lactate would have to be through time or speeding it up with medical ninjutsu. Toughening the body doesn't do much. You strengthen the muscles and they become stronger. Problem is that hachimon forces said muscles to operate at 100% which they aren't suppose to, which leads to them being torn. Conditioning your body would make your muscles stronger and they would still tore themselves apart just like before conditioning since their strength is increased as well. So my guess is that with repeated uses of hachimon each user finds a limit at which his muscles don't tore themselves apart, like say 70-80%, and that's why they can use it without much consequences with practice.

By that logic this cell would be gone either way, because those injuries are inescapable on the early stages of learning hachimon tonko. Even if you don't use medical ninjutsu to speed up its recovery. Letting it heal naturally wouldn't magically repair it. So I don't see any downsides there. I'm not debating how stamina works. I said that feeling exhaustion isn't really necessary to the process of increasing it with medical ninjutsu. At that point it becomes a question of training until exhaustion healing that up and continuing with training. The only reasons to stop training are eating, sleeping, going to the toilet and chakra exhaustion.

By that logic this cell would be gone either way, because those injuries are inescapable on the early stages of learning hachimon tonko. Even if you don't use medical ninjutsu to speed up its recovery. Letting it heal naturally wouldn't magically repair it. So I don't see any downsides there. I'm not debating how stamina works. I said that feeling exhaustion isn't really necessary to the process of increasing it with medical ninjutsu. At that point it becomes a question of training until exhaustion healing that up and continuing with training. The only reasons to stop training are eating, sleeping, going to the toilet and chakra exhaustion.

Gai can open seventh gates several times, but not without consequences. Sure it takes awhile for them to set in, but he does succumb to them. Cells using up their lifespan is so sever for Tsunade because she heals life threatening injuries. Healing after training wouldn't decrease it by that much and ninjas don't live long lifes anyway, at least before Naruto came along and instilled an era of peace. That physical energy bs that Sakura explained in part 1 doesn't apply to enduring exhaustion. It supposedly applies to every cell in their bodies producing energy. So if those cells produce more physical energy due to natural training or augmented one doesn't matter.

Training hachimon already leads to long term consequences. You shouldn't be able to walk off torn muscles and broken bones without consequences. I didn't meant it like Tsunade's Yin seal. More like Kabuto's self healing that allowed him to walk off getting hit by a Rasengan in the gut.

Gai can summon though, remember that Turtle during Lee and Sasuke's fight at chunin exams, so he can use chakra outside his body unlike Lee. As for medical ninjutsu usage for hachimon. Well there's healing your torn muscles to allow for longer usage of hachimon. Then there's the fact that training usually means slight damage to your muscles and bones, which after recovery becomes stronger. Healing yourself after each training would allow to train more since it would decrease mandatory rest period.

I'm honestly getting kind of tired of writing this large comment debate. So it would be the last one. After that we both can just walk away with our own opinion. Dai was a genin partially because he couldn't use ninjutsu and genjutsu, but mostly because he was failing even easy missions. Those easy missions were failed due to him training eight gates every night and suffering from drawbacks during said missions. Essentially he dedicated his whole life to this one technique at the cost of everything else. That would probably inculde increasing his chakra reserves since he couldn't perform ninjutsu and genjutsu. Gai got a very good headstart due to his father's 20 years of learning nooks and crannies of eight gates and passing it on to him. That allowed him more free time to practice other avenues of a ninja's abilities. From what we got in the show constantly depleting your chakra and then allowing it to replenish increases chakra reserves. That was the reason Kakashi made Sakura walk on tree until she tired out. So now that Gai had some free time he would practice with ninjutsu that would be necessary for his promotion as a ninja. That's my reasoning for why Gai is stronger than Dai. I don't agree that you can't improve eight gates as well as hiraishin. It would require knowledge of medical ninjutsu, but if you can master it to the extent of Kabuto with his self healing then using eight gates would become easier. Although that would require something like sending shadow clone to train in medical ninjutsu, while training your body. Gai already made several different techniques that require using eight gates: Omote Renge, Asakujaku, Hirudora, Yagai. Though to be honest I have no idea how he created the last one since it requires opening eighth gate which would lead to death. So if you can have an easier recovery due to medical ninjutsu you would have more time to make new techniques.