@Fleet Admiral Lee Hung
I. "The holy blessings" are not so holy
1. The first point is undeniably true, but it's very important to note that being the son of an incredible person doesn't necessarily mean much in One Piece. This is an important theme in One Piece. Blood related parents are not their "real parents". Zeff is Sanji's father, not Judge, Whitebeard is Ace's father, not Roger (Tom and Franky, Chopper and Hiluluk, Law and Corazon, Nami and Bellemere,.......).
What I mean by this is that Luffy doesn't have an immense willpower because of his father or grandfather.
Very early in the story, Oda showed Helmeppo, son of Morgan. His way of telling early on that if your father did something to earn respect, his son or family members in general should not get the same respect. It is your own actions that count. That's why "Inherited Will" is one of the most important themes in One Piece. It's not about your bloodline, but more about the ideals, dreams, etc. that you carry with you. (Chopper has the same dream as Hiluluk. That's why Hiluluk didn't die because Chopper lives on (with the same dream) and that's why Hiluluk lives on).
2. The conqueror's haki is an interesting subject. Yes, it seems people are born with this ability but that doesn't mean they don't need to develop it. He used it pre-timeskip unconsciously but when he trained with Rayleigh he could use it at will.
3. Meeting a Yonkou is indeed being lucky, but Shanks has met thousands of people, yet he would only give the straw hat he got from Roger to Luffy. Why? Very simply because Luffy had the same dream as Roger (which we don't know at the moment). So did he give it to Luffy because he is Luffy?
The Imu thing is not worth discussing because what you are saying is pure speculation. We literally know nothing about the straw hat. To say he has an obsession is pretty far fetched.
4. Same again. You completely missed Ace's storyline and the major themes surrounding the story. Ace doesn't see Roger as his father and Ace didn't receive training from Roger either. Ace was not the strongest man in the world at 10 years old. At that time there were probably a million people stronger than Ace that Luffy could've received training from so I don't understand your point.
5. Again, Rayleigh taught Luffy because of Luffy's actions not because of plot convenience. He knew from Shanks that Luffy had the same dream as Roger so he already had his eyes on him. But, Luffy hit a bloody Celestial Dragon in front of an entire auction room. He immediately says that the straw hat suits a fearless man like Luffy. They even start talking in the cafe and he hears Luffy's reason for wanting to be the king of the pirates (freedom, not control) and he immediately smiles. Same as with Shanks, Rayleigh has probably met thousands of other rookies, yet he only helped Luffy because of his actions. Why would he help someone like Kid, a guy who hurts civilians, which is the opposite of what Oda wants to tell you.
6. Boa Hancock didn't trust any man because of her past, when Luffy put his own desires aside (covering Boa's sister back, and saving Marguerite and the other girls instead of getting his shiop) whilst having conquerors haki surprised her. On top of that, he is the first man to not turn into stone when he sees her (even naked). Take as you will, Oda tried to bring in several reasons why she would fall in love with Luffy. I personally think they are strong enough but definitely could've been handled better. (I notice that your arguments don't contain the reasons as to why they help luffy or see something special in him. Only thing you write is, Luffy = Christ. Not a compelling argument.) If you think that Boa's reasons for falling in love for Luffy are shallow or not enough then that's fair but it's as if you're skipping the reasons.
7. We don't know why his fruit is so important. I do agree that this is worrying, I do hope he doens't make this the most special devil fruit in existence but that's merely speculation. We don't know any reason as to why the WG wanted the rubber fruit. (But I also would've much preferred if the rubber fruit would've been a weird fruit that luffy happened to eat that he made special by being creative with it.)
Joyboy is another topic that is way to large to discuss, but one thing I can say for sure is that Luffy will not be his reincarnation. Simply because of the major theme of Inherited Will. Yes, Luffy has probably inherited his will altough this is also speculation.
I did read all of your post but it just would take a bit long to answer most of your arguments (if you want to continue this discussion, I would do so). I do feel like your are only looking at the story with what you think it is and without ever thinking what Oda actually wanted to tell.