Basically what I'm primarally concerned with is
1) Does it have a decent 'hook'. Does it seem like a place that you'd want to adventure in and around?
2) Is it clear?
3) Do you get a reasonably good mental image of the city itself?
4) I'm purposely vague about some of the history. Basically the planet is a long forgotten colony of an ancient star faring empire. "The Severing" was a little understood event where interstellar travel suddenly ceased. This led to a massive war on the planets surface that wiped out most of the colonies. Do you think I need more detail though?
5) Keep in mind, I am aiming for a 'science fantasy' setting. I want weird science. However this means I need to come up with an explanation for how spellcasting works. One idea I'm toying with for wizards at least is using nanites that are still floating around as 'patrons' but that leaves priests out in the cold, and the nanites are just one patron... I'd like to avoid psychic stuff if possible, and the 'god is a computer' idea is a little old (looking at you Ultima III) but I'm stuck for other ideas.
6) Please bombard me with ideas for adventures and the like. Help me flesh this out a bit.
Carved of black basalt and squatting like a malignant toad over the mouth of the Gray River Delta the city state of Barasbor has held sway over the eastern Desert of Gol-Than and the Bay of Sorrows for many thousands of years.
An ancient evil city, Barasbor has grown and shrunk organically over the millennia as its fortunes have waxed and waned. The oldest part of the city, the towers of the Star Men also known as the twelve towers stood vigil over the star ships and space boats of the Star Men and still stand like sentinels over the city. The oldest and most noble families have turned these crystalline spires into fortresses, each housing hundreds of loyal slaves, mercenaries and bondsmen in addition to the nobles that rule the city. Some of the greatest treasures in the world are contained within these spires. Ancient technologies and sorceries long since forgotten by the rest of the world, jealously guarded and passed down within the great families.
During the Age of the Severing great walls made of a strange gray metal were built around the twelve towers to defend the city against the great war machines that the Star Men unleashed against each other. Remnants of this apocalyptic conflict remain. The length and breath of the walls bear the scars of the conflict and entire redoubts have been rebuilt using basalt and other materials as the sorceries used to create the original walls have long since been lost. Since the Severing a labyrinthine palace structure has been built within them housing the dozens of lesser houses. Every night blood runs in the corridors and streets among these houses as the lesser houses jockey for position and power within the city.
Outside the old walls lies the New City. This is as far as most visitors will ever enter into Barasbor. From the taverns to the weapon foundries to the slave markets the new city is the beating heart of Barasbor. The nobles of the old city are too concerned with their own power plays and position amongst their peers to pay the New City much mind and so long as the tithes of gold and slaves make their way into the noble coffers the New City is left to its own devices.
Surrounding the New City and outside its much more primitive (though still imposing) basalt walls lies a massive sprawl of shanties eeking out a living in the swamps that make up the delta the city was built on. Years ago the delta was made up of fertile flood plains that served as the cities breadbasket. Over the years however much of the delta has become a stinking mire. The arable land is shrinking and the the poorest inhabitants of Barasbor have begun to feel the squeeze as food prices have climbed.