corporate-wage-slave

I would add Charleston and Nashville to the USA destinations, though a week is perhaps slightly too long. New Orleans definitely has a week of attractions around it, no question of that in my mind. If you can cope with PHL and WAS then I'd add BOS or Montréal+Québec to the short flight list, but both WAS and PHL are good choices, and one can never tire of NYC either. Montréal often has slightly milder weather but essentially you have to plan for a few inches of snow. I'd drop DXB, unless you are into shopping malls, I'm not. Agree with BEY or AMM as an alternative to Marrakech, all are a bit of hard work, but in a hopefully rewarding way. AMM would give you the Petrus option (think about their combined visa+admission card system).

The place that matches your specification best is Muscat, Oman, or perhaps México, though both are pushing your flight time limits.