Welcome to FT!

Flying in economy is never going to be special, no matter what airline you choose. I don't think you'll have had much luck buying a business class ticket for less than what you paid for economy fare, even with all the great insight here. You could have cut one stop out of your journey by flying via London or Frankfurt, for example, but that's about it.

As far as luggage goes, if your trip is all on one ticket, you won't have to re-check it along the way. The exception to this is in Chicago. As this is your first port of entry to the USA, you'll go through immigration/passport control, and then pick up your suitcase(s) from the belt, then drop them off immediately at the re-check desk. It will already be tagged for IAH.