Nobody was focused on Goku when he transformed into SSJ3,
Everyone on Earth who mattered was focused on him:
yet his ki was strong enough to call their attention on Kaioshin Realm, so, everyone on Earth theorically could be able to sense Gohan's ki even if they don't want to,
Yes, theoretically they could sense Gohan from Earth, but if they were focused on EVIL BOO, wouldn't that distract them, & possibly prevent them from sensing Gohan? Especially since that Ki that was distracting them was already somewhat relative to Gohan & right in their face, possibly about to kill them.
yet only Super Buu could sense him from that far.
Since Evil Boo, naturally, wouldn't be distracted by his own Ki.
I agree, Movie 12 Goku can be stronger than Buu Saga Goku, but not that far ahead. Movie 12 SSJ2 Goku is still weaker than Fat Buu, but in SSJ3 he can overpower an enemy even stronger than Fat Buu while needing to go all-out if he wants to defeat the last one in his maintimeline self.
Yeah, if we take them as the same flow of events, then Movie 12 Goku would be stronger by some amount, but I don't think he got strong enough for the difference to matter, personally.
Vegeta was also landing solid hits on Fat Buu initially and his attacks were apparently damaging him a lot, but in Buu's case he can be damaged by attacks make by people way weaker than him. Also Janemba defeated Vegeta easier than Fat Buu.
Vegeta was getting good hits on Fat Boo, then gets defeated in one attack. Vegeta was getting good hits on Janemba, then gets defeated in one attack. My point with that is the degree to which Janemba > Fat Boo probably isn't big enough to really make a difference.
The fact that he can't tank SSJ2 Vegeta's attacks pretty much indicates he was suppressed, we have seen cases in which a gap less than 4x (which is the minimum gap between Vegeta and Janemba) are able to tank characters.
And yet, there've been cases in which characters have been able to affect others despite massive differences, like when Piccolo kicked Freeza in the head so Goku could finish the Genkidama, which would be a gap of up to 60x.
And Janemba was stronger than SSJ3 Goku, but couldn't tank his attacks, so who's to say he could tank Vegeta's.
Vegeta was also getting good hits on Fat Buu initially, your point?
My point, is that it suggests that Janemba is not much farther out of Vegeta's league than Fat Boo was.
Honestly, is there a point to this particular aspect? Would you agree that M12 Vegeta = Boo Saga Vegeta? By that logic, M12 Gogeta = Boo Saga Gogeta, correct?
Buu has only seen Goku using the Kamehameha, when he was Fat Buu, how would he be able to know that everyone else use it?
Because he knows all of Gohan's friends from absorbing Goten, Trunks & Piccolo.
Gotenks dominated Super Buu and was about to blow him up to pieces, yet he doesn't consider him stronger than him, actually he considers himself the strongest before Gohan.
Boo was getting very frustrated in that fight, which would've made him sloppier & easier to beat. Still physically stronger, if even by a smidge, is possible.
Thing is that at this point, Goku could pretty much knows how a Metamoran Fusion between himself and Gohan could be, as well as whether they can defeat him that way or not.
I don't doubt that Goku would know how strong Metamoran Gokuhan would be, but he never states whether or not that Fusion would win, only that that was his plan before being given the Potara earrings. The only thing you can honestly gleam from that is SSJ3 Metamoran Gokuhan > Gohan.
Also, do you think Base Gogeta is stronger than SSJ3 Goku? Because we've seen how Base Gotenks was stomped badly by Fat Buu, even though he has more confidence in himself that SSJ Goten & Trunks when it comes to defeat Buu.
If you assume SSJ Gotenks = SSJ3 Goku, & that Goten/Trunks are 1/2 as strong as Goku, then Fusion would be an 8x boost, at least in Gotenks' case.
Goku = 1
Goten/Trunks = 0.5
SSJ3 Goku = 400
SSJ Gotenks = 400
Gotenks = 8 (0.5+0.5) (x8)
As for me, I just downscale from Boohan
Evil Boo ~ SSJ3 Gotenks
Evil Boo/SSJ3 Gotenks = 3,200
Bootenks = 6,400 - This is about where Boohan lies (6,400+), & where I think SSJ3 Gogeta lies. 6,400/400 = 16 (weaker than SSJ Goku)
But there's also the question of how much stronger did Gotenks get in the RoSaT, & judging by the fact that Piccolo think SSJ Gotenks has no chance against Evil Boo, he sends Goten/Trunks into the RoSaT, & when Base Gotenks squares off with Evil Boo, Piccolo thinks his Base form at least has a chance against someone who would pulverise SSJ Gotenks (Pre RoSaT). That would imply Base Gotenks (Post RoSaT) > SSJ Gotenks (Pre RoSaT). So if you think that, multiply those figures by 50, which would make Base Gogeta 2x stronger than SSJ3 Goku.
SSJ Gotenks (Pre RoSaT) = 400
Base Gotenks (Post RoSaT) = 400
SSJ3 Gotenks = 160,000
Evil Boo = 160,000
Bootenks/Boohan ~ 320,000
SSJ3 Gogeta ~ 320,000
Gogeta ~ 800
Yes, I do believe Base Gogeta > SSJ3 Goku
Old Kaioshin knew that Gotenks & Super Buu were fighting inside the Rosat,
I don't see your point.
as well as Goku afterwards claims that Gogeta can defeat Super Buu, is that also not proving anything to you? Also, you didn't responded my question.
Source the text in bold.
Sorry, I don't see a question? Unless you mean this?
This is like if I ask you to prove me how much of a confidence does Buu have if he want to stop Goku & Gohan fusion on his capabilities of defeating him.
Well, judging by the fact that not even a bead of sweat drops from his face when he thinks about Gokuhan, probably a lot of confidence.
He fought a SSJ3 Goku that was holding back (but he didn't knew). He doesn't seem to have a good grasp at how strong Goku is, though, as he think he could defeat him as Fat Buu.
I don't think Goku was holding back, throughout the fight with Boo, you can read Goku's inner thoughts & he's constantly surprised by Fat Boo, first by how he can't damage him, then by him copying Vegeta's Technique™. Especially considering he had minutes at most left on Earth.
SSJ2 Vegeta ~ SSJ2 Goku, so by that logic Boo would know how strong Goku is, regardless of whether or not he thought he could beat SSJ3 Goku, holding back or not.
Also, he doesn't seem to know that SSJ3 Gotenks was actually stronger than him.
See previous
Maybe because he doesn't know how Fusion could work on different races? Also Buu literally said that another human with great power has appeared.
That's clutching at straws, nobody knows how Fusion could work on different races, only on Metamorans, Saiyans, & Human Saiyan Hybrids.
In translating Japanese -> English, I think Human can also be just Earthling, not necessarily literally Human.
Because Gotenks was stronger than him.
See previous
Buu already showed to take care of Dabura, Gohan or Vegeta, he couldn't scratch SSJ3 Goku.
Where exactly do you place Fat Boo? He has to stomp SSJ2 Goku, so how far behind an SSJ3 Goku can he possibly be?
I think that Gogeta is stronger than Ultimate Gohan, he can also be stronger than Gotenks Buu, but doesn't know exactly for sure by now. I don't think Gohan Buu could beat him, but I can't also imagine Vegetto being that much above Gogeta.
Speaking of, where would you say Vegetto fits into it? You probably already know where I think Vegetto fits, Base Vegetto > Boohan > SSJ3 Gogeta.