The Gorn/Forstford mod probably won't work under latest version, I now know it has no survivability, so check the code directly.
For me, the two biggest bugs in the game are (1) the autocombat glitches in the next battle when you kill the final enemy using autocombat and (2) no save/load of guild contracts (or slaves) allows exploiting. The autocombat thing looks seriously hard to track down and it might involve UI files we can't mod. I'm assuming the save/load problems will require a undesirable change to the save file format.
There's another frequent display bug where the group panel is not updated after you buy or discard items. It could also happen at other times, such as after combat. It might be hard to pin down all the occassions but this is fixable.