I tried that for a while, and found it immensely difficult to do. When you offer to do Baal for quest, people assume that the high level will PK them. Perhaps this is only in HC, but still, I've found it difficult to do. As a way around this, I've leveld up a char to do the rushing in Classic. That way, you don't have to worry about the ancients or A5 at all. Just rush the char straight up, and then convert it to expansion to do the forges.
As a side note, this bug works for every quest that a char is elegible to get. If there is a character who needs the quest in the area necessary to get it (i.e. Sewer 3 for Radament, the Den for the skill point, etc.) then you can get the quest by being partied and standing in town. This can be useful if you're running through the game. Have the second copy open, with the partied lvl 1 sitting in town, and they'll get all of the quests as you run through the game.