This question contains spoilers…
(view spoiler)[I listened to the audio version in a hurry and had to return it already. I have 2 questions: both answers would be spoilers. 1. Was Val's wife killed by JG or was it her friend? 2. Who was the woman (body) found by VM in the reeds who had made a tube to breath through and had injected herself? with drugs? I hate it that I can't listen again to figure these things out. (hide spoiler)]
This answer contains spoilers… (view spoiler)[My understanding was that Gload spared Glenda's life because he considered Val his friend in his own warped way. Gload took her necklace to prove to Val that he could have killed Glenda if he had wanted to. He did not kill the roommate Jean thinking that she was Glenda. The girl Val found buried who had killed herself was a rape victim who had wanted to disappear and never be touched again by anyone. Her name was Penelope Ann Carnahan, "your name is a poem."