Thanks for the info Killap, and a bigger thanks for your great work on making FO2 playable.
You might be interested to know tho that I just finished The Den and I did have a major lag issue once, and yes - Petey was on the screen. It went away after a short period of time, so it's no big deal. I'm only mentioning it because I saw the release notes which said that it had been fixed. And on first arrival at the Den, there is a random chance that the screen will be black (not "blank") everywhere but where the character is. It happens maybe 1 out of every 10 or 15 arrivals (I'm reloading my final Klamath savegame trying for a specific encounter enroute to Den). When the screen is black, it acts like it covers the unexplored area only while it remains unexplored. In other words, the black disappears everywhere the character goes. Reloading a previous savegame always corrects the issue.
I also had a problem where the back door of the Slavers Guild wouldn't open after I'd killed all the slavers. Dynamite fixed it. I ran into the same thing when I had RP1.2 installed. It doesn't always happen, but reloading a savegame will not fix it if it does.
Good luck with your project. I did the same thing for Morrowind, so I have an idea of what you've gotten yourself into.