Trying to pickpocket 1500 gold. I have a 12% chance. I put on 1 or 2 items with increased chance to pickpocket and my %chance drops from 12 to 0. Doesnt matter if i wear 1 or 2, it stays at 0.

There is a known bug where if you have a high base pickpocket chance, via skill level +perks, putting on some pickpocket enhancing gear makes the value go down because it gets so high that it resets to zero, then starts adding up from there.

As far as I am aware, there is no workaround, I am not sure if the unofficial Skyrim patch fixes it either.