The map and layout are really good, bravo. The dungeon has secondary entrances, secrets, and factions galore. The NPCs all have motivations. Yum!
This adventure is good, and is runnable with some work. But I have some nitpicks because I think this adventure could be truly great with a few tweaks.
I would have loved to see all the monsters in the keys. For example, the faction section lists the the turtles but the key doesn't explicitly mention them. The GM needs all the key info in the key to run! Otherwise they might forget to put the turtles anywhere. Some rooms mention the monsters, some don't. Likewise I'd like to see more interactivity and specific detail in some of the rooms. The showroom has some tiles trapped with darts, but which ones? How will the players interact with this to figure out and avoid? The royal bedroom hides a key but there's no clues to check under the carpet. Maybe a note, NPC dialogue, or even just it looks the carpet was recently moved would add the needed layer of detail for players to really engage. And just from a runability standpoint, some stats or what monsters from Shadowdark to reference would make it easier to run.
But don't get me wrong, this is an excellent submission and for real art. You should be proud. Great work!