Exactly! The same God, but some wrong ideas about him.I think, Paul say they have wrong concept about God and Paul will correct it.
That's correct that they didn't worship Jesus, but they cannot worship someone they haven't heard about.They don't worship Jesus if they worship Paul god they not worship idol
It is possible to worship both the true God and give honor to false gods as well, as the people living in Samaria were doing.
2 Kings 17: 33 They gave worship to the Lord, but they gave honour to their gods like the nations did from whom they had been taken as prisoners.