I'm glad you liked my "no level caps" idea. I thought of it while watching someone play World of Warcraft at level 60('twas 3 years ago, that was the cap), and commenting about running into monsters that were higher than his level, and thinking "why?"
It pretty much went from there. To facilitate players who can access unlimited potential, the world has to have an equally unlimited potential, meaning that as you travel further in a given direction, generated enemies will get more powerful, and to take some of the load off of the Devs, player-built equipment should be important.
I also like the idea of adding fashion sense into an MMO. Just because I don't have any doesn't mean it shouldn't exist :p
Another major advantage I think it has is that it theoretically eliminates the "grind to level cap," and keeps the game new. That's one reason I never picked up Guildwars. Sure, it has no subscription fees, but I couldn't stomach the level cap.
Of course, it could do exactly the opposite. I think no player levels but uncapped skill levels is a nice compromise.
As for maps, I think you should look into developing a map generator. No matter how pretty your 2D maps are, they can still be broken down into component parts: towns, shops, roads, trees, mountains, walls, and tilesets. Ultimately, it comes down to: checkpoints, obstacles, groups, events, and graphics.