It was as I feared: Throne of Bhaal is incomplete:(. The Grove of the Ancients doesn't exist. I haven't been able to complete the first quest in the pocket plane (AR0315) and leave the area. Cheat-jumping, and cheating in items, will be crucial if you want to do any of the remainder. I'll keep you informed.
Here's some temporary instructions for cheats to get you through Watcher's Keep:
Complete level one (AR0312) after speaking to the Knights outdoors(AR0313), because after leaving the area, the main door will remain closed. Talk with Brother Pol for the vigil stone and the incantation scroll. The Statues in the main room didn't all go hostile for me, but I couldn't damage them even when they were hostile:(. Ctrl+Y kill them to progress. In level 2 (AR0329) the Ice room has an instakill effect, and the air room has an unconsciousness and high damage effect, this makes no sense atall. You can try stuff out, but ultimately all you need in the 4 circular rooms, are _plot03A, _plot03B, _plot03C, _plot03D, _ompon12 and _blun30A. So cheat these items in with ctrlaltdelete:createitem("[itemname]"). The rest of the areas are accessible, so fight monsters, detrap, plunder, etc. Level 3 (AR0324...) hasn't even been converted for the most part. Unfortunately you must just jump to that area, collect the items there, and also cheat in: _sw1h64, _helm29, _chan20*, _sw1h68, and unfortunately the Deck of Many Things doesn't exist either

. You must also jump into level 4 with movetoarea("AR0335"), and be prepared for a fight. All the quests in this area seem ok, except the machine of Lum the Mad. It doesn't work atall, you can't enter a third combination, so you always get a 'punishment' effect. The demi-lich on this level can instakill you, so use disrupting weapons (Azuredge, Mace of disruption) to beat him to the punch! When jumping into level 5 (AR0343), be prepared for a fight again. Like me, you may not be able to enter the sub-areas for the Helmite ghost's challenges, but after I jumped to one of them (AR0337, 0338 and 0339), the others were accessible normally. The 'Spirit' challenge in the north doesnt work atall, so just cheat in the key _plot05C.
Demogorgon (AR0336) is tricky, since i can't seem to read the incantation scroll to imprison him. So I plot along and see what happens. Whatever you do, you can still reach that area from outside, through a tiny 'crack' in the 5th door, just like in the regular game. Good luck fighting him, i wouldn't be surprised if he just 'pops' if you use a disrupting weapon

! The most XP can be gained by simply killing Demogorgon, and then going outside to kill the Vigil Knights (they give you the most XP). you complete the quest this way, despite not being able to use the incantation scroll.

That's where I am so far, I'll try to see which parts of Saradush can be completed soon...