Hmmm. I haven't tried the Chameleon Skin to loot an NPC. However, the way you are using it ryrytiedye, creates some interesting ideas.
This will require at least 3 characters. Driftwood Square that has people all over the place. You can unchain the invisible character to go grab an item or 2 quick. Keep your group around the corner in a quiet area. Then when they go to accuse someone, you your actual thief (maxed out Thievery + items to augment) to do the main heist.
For the record, if I don't mind adding a couple hours to my Ft Joy time, it is pretty easy to get to Alexander with 50k to 70k gold on hand and a bunch of purchased level 1 and 2 skill books. This gives loads of options even swapping to a completely new party make up once on the Lady Vengeance.
