Yeah, the cave and dungeon generating tables produce some decididly non-euclidian architecture. But I can see there being fun in just letting the players do the mapping, and the DM just calls out each segment, (and then listens to their theories about how they can make 5 right turns with crossing their own paths) In the end its pretty old school to have a dungeon or cave system that (much like a room of beholders) it is just wiser to walk away from.
The Lurid Lair section was the toughest to sort out. This post got me thinking about how encounters are sort of backwards. You first roll for an encounter, and then roll to see if the monster was encountered in its lair. So there is never any chance of encountering a creature´s lair when it is not home. (that post argues that there was another roll in FFC that didn´t make it into D&D.)
The Lurid Lairs section is written as a way to flesh out a creatures lair, after you have encountered it randomly. for the rules I have been working on, it made more sense that the PCs find the lair, and it is defined by the tables, including the creature that occupies it. i.e. ideally the players find a cave, and have limited knowledge as to whether it is long abandoned, or it may be full of Owlbears- or the owlbears stepped out for some smokes and will be back in 5.
So I ended up writing up the encounter tables for all the lairs on my own. They are probably horribly unbalanced, but the chance that no one is home helps compensate. There are a number of occations in the tables where they seemed to have run out of space, and seemed to have left off some key charts. So I tried to fill those out for use in my game.
I am actually most entertained by the Temple rules. I baked in the god generation rules I posted here on the wiki a few months ago. Testing it out earlier I rolled up:
The Temple of Kalailstustet´s Helm
A brick Rhomboid temple of the insane forgotten dwarven god of lies. There his high priests and their 41 clerics worship his helm 3 times a day in a closed ceremony. Their god performs the mircle of shower the faithful with treasure, but (somewhat dickishly) makes them take a vow of poverty. Also he has a lizard´s tail.