If you intend to run the path from adventure 3 out, you cannot set it in Sharn. The problem is that one of the adventures, Foundations of Flame, takes place when the volcano underneath Cauldron erupts. Now, unless you want to put a dormant volcano under Sharn and blow up half the city, well, you may want to just forego that.
I would reccommend using Cauldron but setting it elsewhere in Eberron. It can be done, and relatively easily, if you make sure and put Cauldron way out on the fringe somewhere.