Though the English major inside of me cringes, the DM inside congratulates you on a fun adventure! I do have a few comments, though.
Combat in 4e is vastly different from combat in 3.xe (at least of what I've seen of 3e, I've never played). You should add a lot more variety in terrain and such in the dungeon to make each combat memorable. Don't scatter random combat encounters around unless they help tell the story.
Also, and this might be more of an opinion thing, but treasure isn't randomly determined in 4e. The treasure parcels in the DMG are fair enough, and easy to place throughout the dungeon. All the treasure should be given, no more, no less. If the players miss treasure you had planned, you stick it with the next treasure parcel. If they decide to search bodies that you had planned not to be holding anything, reward them by giving them treasure, but take it from a future treasure hoard so it evens out. Make the treasure be a reward for clever thinking and exciting theatrics, not randomly scattered in boring trapped chests.
Also, I didn't read too carefully, but I didn't notice any skill challenges. They're actually quite fun, despite the problems many DMs say they cause. My players frequently tell me that they have a lot more fun with skill challenges, primarily (I believe) because challenges are good at telling the story and they are quick and easy to understand, while combat is slow, sometimes meaningless, and can get clogged with rules problems. Even in a dungeon, skill challenges can be fun. Try to convince the gang members to let you through instead of just killing them. Get through a hallway rigged with twenty or more dangerous traps. The players will love the simplicity yet dramatic turns skill challenges present.
So, that's my two (or ten) cents. Good work, and good luck!