The characters we're talking about, who Regina cursed, are not slaves or servants.......no, they're not all princes or princesses, but it doesn't mean they weren't happy. I really don't see what would be so great about living in Storybrooke. It's like a small town with no growth; there's nothing going on and, IMO, it's all completely fake because of the curse. If the writers choose to end the series with the characters having a choice, it won't be a deal breaker for me, but I've always wanted and thought that Storybrooke would be destroyed by the ending of the curse. That's why the sheriff dying was no big deal; as the huntsman, he'd still be alive in the fairy tale world.
The characters we know aren't slaves or servants, but the spell grabbed everyone
in their world regardless of station or their relationship (or lack thereof) to Snow White. It's hardly worth it for us to have an episode focusing on the life of Bob the Pig Farmer, Susie the Scullery Maid, or John the Leper, so we'll probably never see any of those characters backstories or Storybrooke lives represented on the show. But, just like our world, I think that Storybrooke is full of plenty of people who are desperate for a change in their circumstances and would see life in our world as a fresh start.
Once the curse is broken, there's no reason for them to stay in Storybrooke specifically if they don't want to. As Mr. Gold confirmed with his "I'm planning a trip," line, they'll be able to leave the boundaries of the town and go anywhere in the world they want. And if that's true, then I also assume that the world will now "see" Storybrooke, and the townspeople will be able to interact with the outside world and develop a real economy, court new residents, build new facilities, etc. They can keep the small town feel (which they might be more comfortable with since that's what most people in the era Enchanted Lands is meant to represent would have known) or they can expand out.
Regarding Sheriff Graham, dead in our world equals dead in the Enchanted Lands too. The characters in Storybrooke aren't duplicates of their Enchanted Lands counterparts; they're the original characters with their minds erased. The Huntsman will appear in Enchanted Lands flashbacks, but he's dead and gone as far as the show's current events are concerned.