God.rains & imluvdbyjesus:
I prefer to respond to your revised logline line here in order to maintain the continuity of the discussion thread. (If you choose, you should be able to revise the logline at the top of this thread and delete the other one.)
So:
Transported with a group of his peers to an otherworldly gallery of paintings that become portals to strange worlds, an unpopular teen must overcome his insecurities and lead this band of misfits back home before the sinister evil that brought them here entraps them forever
Okay, now you've identified a protagonist. But what's the big deal about the kind of portals -- why do the portals have to be "otherworldly gallery of paintings"?
And of all the people of all ages traveling through the Bermuda triangle, why are these kids targeted to be entrapped by the sinister evil? Why doesn't the sinister evil entrap a boat load of, say, retirees on a Caribbean cruise? Or a boat full of Haitians trying to escape poverty and start a new life in the United States? Why are the teenagers so "lucky" to be singled out?
Finally, are you aware of the "Hero's Journey" paradigm as applied to plotting?