Heh. My explanation of Q1 is that it's a plot by Eclavdra to kill or weaken Lolth. Send a party of foolish surface-dwellers against the demon-spider and see what happens. Weaken her enough and perhaps the EEG can then take control...
Of course, I don't accord Lolth status as a deity, seeing her as a malign figure who has lured many disaffected elves away from their true gods; she's definitely slayable by groups of great power and intelligence. (Even if foolish enough to be tricked by Eclavdra).
D3 was the first module I ever bought. The GD series remains as a series I've yet to run or play. It's on my list of things to do, but there are lots of interesting things happening in my current campaign that spawn more adventures, of course!
Cheers!