REPSONSES:
I've probably put about 300 hours into this repack so far.
I can say with certainty that all classic dungeons are functional with the following limitations:
Deadmines spawns the Heroic bosses when you try it normally
The Nefarian fight in Blackwing Lair doesn't function properly, and GM commands do not seem able to bring him in to function properly
I can't get Ragnaros to spawn in Molten Core, but he can be spawned in with GM commands
C'thun phase 2 doesn't start properly, but can be spawned in with GM commands
Baron Rivendare doesn't appear properly in Stratholme, but he can be spawned in
The door to enter Scholomance doesn't function, however, GM commands can be used to give the player the ability Blink which can get through the door
A couple things in Dire Maul aren't quite right, but for the most part the mobs all work. Unless you're doing an old Tribute run, you'll be just fine
Other than that, I'd say that, yes, all of the classic dungeons are functional, though every once in a while you'll have to use a GM command to bypass a door or kill a certain enemy. I'd call it about 97% working, and over 99% things that can we worked around with commands. I personally was very satisfied once I learned my way around the GM commands.
As for you, Yo,
Yes. You can change lines in the config file to have players instantly level 85, or you can just jump them there manually with GM commands
