Akainu will want to kill everyone per his absolute justice mindset. So even for Bonney, if she were to join Luffy against Akainu in the final war, he would without hesitation kill her given the chance. Bonney being his daughter does fit so I’m assuming this in the above potential portrayal.
This is true but the WG and him are like the romans and the catholic church.
One Piece is not a treasure,i'm sure the Gorosei will know what it is but they don't know it's exact location.
I probably agree with the Romans/Catholic Church analogy, but I am very vague on my knowledge of related history. Oda from super early on in the SBS confirmed One Piece is an actual "treasure" in addition to the history/world changing "power" that also comes with it.
I will point out that Akainu is the type of protagonist you want. He is a "kill first, ask questions later". Yes, Oda's morals first rule that is universal throughout the entire series holds this back from getting what you want, but I'm kinda surprised you aren't more of an Akainu fan now that I think about it. A lot of his key character traits match what you like.
So let me ask it this way: if this theory does go through, and Akainu starts his own army to go out and "kill first, ask questions later", would you like that as the plot?