As for this Lolth-binding-Tharizdun bit...
Yeah, that doesn't work for me, on a couple different levels.
First, Tharizduun really ought to be a force of nature (or un-nature?) even to the gods. The notion that any
single god is largely responsible for keeping him imprisoned doesn't fly; it really needs to be a group thing.
Second, I realize that he's trapped in the Underdark, but honestly... If any single god
were responsible, shouldn't it be, I dunno, the god of jailors?

(That was always the case in my own envisioning of the cosmos, until I learned that Torog is trapped.)
And third, I don't really care for anything that brings Lolth front-and-center. To me, except amongst the drow (where, of course, she's preeminent), she really ought to be a sneaky, skulking god, scuttling around the periphery of history and the cosmos, and not
directly involved in anything except her own schemes.
I really like most of the 4E cosmology/theology, but every now and again there's a major detail that just rings wrong for me. This'd be one of 'em.