Now, that's cool, obviously, 'cause fantasy cities may as well be badass if that's what you're in the mood for ... but you're right that it'll require a non-traditional approach when mapping, something more like a modern-day city map than a style suitable for an ancient or medieval one. Stick to showing major streets only, and naming your districts and major landmarks. In other words, you're on the right track, just keep on with that, IMO.
On the other hand, I readily admit that I have no idea if I'm reading the scale-bar right. Clarification on that, please.
Edited Addition: I love the name of "the dammit wall".