Which part of Quran really mentioned that Islam's goal is to dominate the world?

none..

Quran (9:5) -

"So when the sacred months have passed away, then slay the idolaters wherever you find them, and take them captive and besiege them and lie in wait for them in every ambush, then if they repent and keep up prayer and pay the poor-rate, leave their way free to them."

Quran (9:29) - "Fight those who believe not in Allah nor the Last Day, nor hold that forbidden which hath been forbidden by Allah and His Messenger, nor acknowledge the religion of Truth, (even if they are) of the People of the Book, until they pay the Jizya with willing submission, and feel themselves subdued."

Please understand that it says clearly, fight all those that do not believe in Islam till be become Muslim or are dead.

Quran (2:191-193

And kill them wherever you find them, and turn them out from where they have turned you out. And Al-Fitnah is worse than killing. And fight not with them at Al-Masjid-al-Haram (the sanctuary at Makkah), unless they (first) fight you there. But if they attack you, then kill them. Such is the recompense of the disbelievers.

if they cease, then Allah is Oft-Forgiving, Most Merciful

And fight them until there is no more Fitnah (disbelief and worshiping of others along with Allah) and (all and every kind of) worship is for Allah (Alone). But if they cease, let there be no transgression except against Az-Zalimun (the polytheists, and wrong-doers, etc.)

Now, a Muslim is going to say - Hey look. It says " turn them out where they turned you out.", conveniently covering up "kill them wherever you find them" and "fight them until there is no more Fitnah (disbelief and worshiping of others along with Allah) and (all and every kind of) worship is for Allah (Alone)"

"fight them until there is no more Fitnah (disbelief and worshiping of others along with Allah) and (all and every kind of) worship is for Allah (Alone)" is where it clearly says to fight their Jihad till ONLY Islam is left in the World, not just Dominate the World.

Those are, actually, the Key Message.

I wouldn't read that thing if my life depended on it, but the Holy Bible hints around to it...

Revelation 20:4 King James Version

And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years.

that message is plastered all over the quran