Moander could be an acceptible substitute for Mr. T if there hasn't been any campaign emphasis on him lately, or if your particular timeline has him still being alive. Otherwise, I would leave Mr. T alone and just assume he is Ao's big brother, locked away so long ago that even the current crop of gods don't remember him. That also allows for a proper amount of mystery in the adventure.
The gods he duped are easy to change. The only difference between Bane and Iuz is their home planes, Lolth is around in the Realms too, and Zuggy can be shifted to nearly ANY female evil Realms god (Beshaba, Talona, and Auril all seem good choices... Umberlee wouldn't care and Shar wouldn't be fooled).
Locating the towns is probably the most difficult part. I decided to place Hommlet (kept the name) near Highmoon. This allowed the PC's access to a reasonably rustic good realm, with easy access to Sembia for the big purchases/sales they will need to make to survive! The Crater Ridge Mines were located at the spot my FR Atlas puts "The Heart of the Mine", and the Temple of EE itself is inside the dark area at Darkwatch.
Rastor and Nulb are optional, particularly if nobody played the original ToEE. In my campaign, the PC's literally stopped once in Rastor for directions to the Mines, then never returned. Nulb is basically a camping place for a particular NPC, and a DM can easily remove the entire site and put the NPC somewhere else reasonably nearby.
One fun little element you can use is the fact that ALL gods, regardless of alignment, HATE Mr. T and will want him to stay imprisoned. Discomfort the party a little with Fzoul Chembryl (or some other big cleric of Bane) offering them honest help, and smile with glee as you describe the items he gives the PC's in the most sinister way possible! Owing a favor to a powerful cleric of Bane is not a situation most good guys want to be in...