Maybe an idea to circulate the population (as well as the great ideas above) could be a "tax system" on retainers. This is not for just Uldar, but whichever city turns the most popular on that week.

For instance, a 10% tax on retainers un Uldar on week 1, the larger population move to Limsa Lominsa, wee 2 tax is 10% in LL. The cycle of course moves on