Rob, I think you misunderstood me. As far as US Airports and security personnel goes - IT DOES raise a flag. Will you definitely be pulled aside for a special search? Can't say, but traveling with a one way ticket increases the chances that you will be. When traveling in the US, you hand over your ID to the check-in person who then ONLY sees your one way ticket to anywhere. It is then up to them to stick that little "SSSS" mark on your boarding pass which means "Special Search (SS, lol)". Not sure how this works if you check in online...might work the same without the obvious markings.
As far as getting TO and being IN a Jamaican airport with a one way ticket - I wasn't SURE if there would be a problem or additional time spent at immigration. I really can't speak from experience on that but I certainly can regarding US airports. I'm in one at least once a month (god help me). And I've had inane issues come up leaving Jamaica from "improper luggage tagging" to seat assignments - that has taken extra time at the counter in MoBay.
So just to be clear - my words of caution are regarding traveling out of a US airport as the OP will be. I travel by air all the time, once a month every month except for the months I am in Jamaica. I am very in tune with TSA, Homeland Security and their various whims to protect our skies. I'm really not speaking out of my butt here. Truly...
Go ahead and do the one-ways if its easier/cheaper. Just be aware of what the climate is at the airports in the US and leave time. You have nothing to hide, you've done nothing wrong but there's a good chance you'll get some extra questions and screening.