Finally--and this is what really convinces me--moving his ascendant back to 29 Leo puts his fifth house cusp at 1 Capricorn, which in turn puts his moon and Uranus conjunction in the fifth house. Between his behavior in the time leading up to the shooting spree, his stated motives, and the karmic story I see emerging (moon is the ruler of his south node, so important in the south node story), fifth house makes much more sense for those planets than fourth. I'll have to post again about that because I don't have time to go into it right now....
And what I started to say before the discussion took some other twists and turns:
His big obsessions seem to me to have everything to do with his fifth house placements in Capricorn, and it makes the most sense if his moon and Uranus were also in the fifth house. Reading up, it looks like the main thing he was obsessed with was pleasure and that he wasn't having it. He said he envied couples because they were happy. He wanted to kill people with the most active sex lives because they were getting the most pleasure out of life.
http://www.cnn.com/2014/05/25/justice/california-shooting-revelations/
Fifth house is about pleasure, and Capricorn is restrictiveness. But it's not just that he had his fifth house cusp in Capricorn, or even that he had multiple fifth house Capricorn placements. I think what really got him on that downward spiral was that he'd gone that route in the karmic past and never reoriented himself.
Moon rules his south node. In reading the south node story, we read every placement involved for its negative meanings. If the south node ruler is in Capricorn in the fifth house, that suggests a karmic past in which he had a dogged and dreary approach to pleasure, doing plenty of things that should be pleasurable but never getting any real enjoyment from them. In other words, addictive behavior. A hardcore alcoholic gets little or no pleasure from drinking. A gambling addict gambles obsessively, like a chore. Even getting addicted to computer solitaire can turn into that kind of drudgery.
His moon is in stellium with the very planets that suggest escapist behavior/addiction (Neptune) and gambling and other pursuits with unpredictable outcomes (Uranus). Neptune is in opposition to his south node, as is Uranus if we use a very wide orb. Moon is out of orb of opposition, but because of its affiliation with Uranus and Neptune, I think it's safe to count it as an opposing influence. In the karmic story, what's in opposition to the south node indicates what was an insurmountable obstacle in the past. South node's ruler in opposition indicates that he was his own insurmountable obstacle. Neptune and Uranus indicate addiction; Uranus in particular suggests a gambling addiction, although substances and other addictive behaviors could also have been involved.
Rodger wasn't just obsessed with the pleasure and the girlfriend he didn't have, he also got obsessed with wealth. His family was well to do, but not rich enough by the standards in his mind. In the months before he died, he decided he deserved to get rich and would do so by winning the lottery. He obsessively played lottery and powerball, driving back and forth between California and Arizona to buy tickets in both states. When he didn't win, he spiraled more out of control.
Sounds like a perfect case of moon/Uranus conjunction in Capricorn in the fifth: Capricorn drive to get rich and be on top, moon making it a deep emotional need, and Uranus suggesting that the way to do it would be to do something with an unpredictable outcome. In the fifth house, games fit the picture best. If he'd had that same conjunction in the sixth house instead, he probably would've been inclined to work for his money instead of play for it, but he'd probably have chosen a form of work that resembles gambling--being a stockbroker, for instance, or flipping real estate. If the conjunction were in the fourth house, he'd have probably gone into real estate, fourth house being connected to land. Gambling? Fifth house.