@mrpmiller: I've looked quite heavily into the code that determines advancing from one chapter to another:
Prelude: The only requirement is to get two conversations at the end, one with Fenthick or Desther, one with Fenthick, then complete the conversations naturally. This automatically levels you to level 3 (important now that I'm skipping the trigger to get to level 2). Incidentally, on that subject, I found a setup for the Academy clip that's not exactly reliable, but is at least reliable enough to attempt on a run. Haven't finished a run using it yet, though. This gives me a pretty unusual problem: because I skip the trigger to reach level 2, I only have one sorcerer/wizard complement of hitpoints at the Mysterious Mage, which is not enough to survive Magic Missile. My current solution to this is to cast Daze at him; it goes off first due to the game's perception rules, and if it lands (around a 40% chance), the Mage is dazed long enough to run past him without getting missiled. A 60% chance of run over is pretty nasty, though. At least it's early.
Chapter 1: I haven't found any exploit in Aribeth's conversations here (at least with respect to advancing to chapter 1e). Each of the four components is checked for separately, by its own item tag. Thus, your only choice here is to recover the four items in question. It doesn't matter how you get them, but I don't know of any way (short of debug mode) to produce items without going to a location where they exist in the game world, or running a script that gives them to you.
Chapter 2: The trigger to move onwards only cares that you turn in two journals; turning in the same one twice is fine. This badly breaks the logic of some of the other journal entries, but you don't care about those. (Actually, the logic for the chapter 2 main quests is broken anyway, even if you don't duplicate items. This could make 100% quite awkward.)
Chapter 3: The game has code to prevent you turning in the same Word of Power more than once. However, due to a scripting error, it doesn't run if your Charisma is lower than a certain value (I forget what it is offhand, it's somewhere around 14 though). Naturally, I found this out during a run attempt trying out a higher-Charisma route.
Chapter 4: The only item-based plot gate is on the Chapter 4 Word of Power. This has a different item tag internally than the one from Chapter 3, so sneaking a Chapter 3 Word of Power into the module wouldn't help anyway.
I reinstalled the game recently onto a USB stick in the hope that it would make load times faster, but it actually made them slower, so I put it back onto my hard drive. On another, mildly amusing note, when I was semi-casually completing the game (i.e. I spent about 3 hours) in order to unlock everything that could be unlocked, I managed to die in Astral Pocket of all places, and the "respawn" button isn't disabled. Strangely enough, this doesn't softlock the game, even if you go and die elsewhere in order to reset the respawn point; you can play through the Source Stone again, and when you come to the Inner Sanctum, it's full of spell animations and there's a portal next to where you enter. It does mean that the plot of the game makes absolutely no sense, though (in fact, Haedraline was still asking me to get the Word of Power, and the only evidence that anything had changed in the game world was that Aarin was aware of Maugrim's death; this was probably a consequence of the Aribeth skip).
This is clearly useless for speedrunning, of course, because if you're in Astral Pocket you should just go win the game. It's pretty amusing, though. (I then spent something like 10 minutes trying to recreate it. You have to get hit by the Hand of Morag just as you're running through the portal. The timing is surprisingly tight for something so useless.) If it happens in a real run, by the way, just click on the priest, hit 321, and keep going.
Prelude: The only requirement is to get two conversations at the end, one with Fenthick or Desther, one with Fenthick, then complete the conversations naturally. This automatically levels you to level 3 (important now that I'm skipping the trigger to get to level 2). Incidentally, on that subject, I found a setup for the Academy clip that's not exactly reliable, but is at least reliable enough to attempt on a run. Haven't finished a run using it yet, though. This gives me a pretty unusual problem: because I skip the trigger to reach level 2, I only have one sorcerer/wizard complement of hitpoints at the Mysterious Mage, which is not enough to survive Magic Missile. My current solution to this is to cast Daze at him; it goes off first due to the game's perception rules, and if it lands (around a 40% chance), the Mage is dazed long enough to run past him without getting missiled. A 60% chance of run over is pretty nasty, though. At least it's early.
Chapter 1: I haven't found any exploit in Aribeth's conversations here (at least with respect to advancing to chapter 1e). Each of the four components is checked for separately, by its own item tag. Thus, your only choice here is to recover the four items in question. It doesn't matter how you get them, but I don't know of any way (short of debug mode) to produce items without going to a location where they exist in the game world, or running a script that gives them to you.
Chapter 2: The trigger to move onwards only cares that you turn in two journals; turning in the same one twice is fine. This badly breaks the logic of some of the other journal entries, but you don't care about those. (Actually, the logic for the chapter 2 main quests is broken anyway, even if you don't duplicate items. This could make 100% quite awkward.)
Chapter 3: The game has code to prevent you turning in the same Word of Power more than once. However, due to a scripting error, it doesn't run if your Charisma is lower than a certain value (I forget what it is offhand, it's somewhere around 14 though). Naturally, I found this out during a run attempt trying out a higher-Charisma route.
Chapter 4: The only item-based plot gate is on the Chapter 4 Word of Power. This has a different item tag internally than the one from Chapter 3, so sneaking a Chapter 3 Word of Power into the module wouldn't help anyway.
I reinstalled the game recently onto a USB stick in the hope that it would make load times faster, but it actually made them slower, so I put it back onto my hard drive. On another, mildly amusing note, when I was semi-casually completing the game (i.e. I spent about 3 hours) in order to unlock everything that could be unlocked, I managed to die in Astral Pocket of all places, and the "respawn" button isn't disabled. Strangely enough, this doesn't softlock the game, even if you go and die elsewhere in order to reset the respawn point; you can play through the Source Stone again, and when you come to the Inner Sanctum, it's full of spell animations and there's a portal next to where you enter. It does mean that the plot of the game makes absolutely no sense, though (in fact, Haedraline was still asking me to get the Word of Power, and the only evidence that anything had changed in the game world was that Aarin was aware of Maugrim's death; this was probably a consequence of the Aribeth skip).
This is clearly useless for speedrunning, of course, because if you're in Astral Pocket you should just go win the game. It's pretty amusing, though. (I then spent something like 10 minutes trying to recreate it. You have to get hit by the Hand of Morag just as you're running through the portal. The timing is surprisingly tight for something so useless.) If it happens in a real run, by the way, just click on the priest, hit 321, and keep going.