Still catching up with this thread, so forgive me hitting points as I go along:
Fact: Lower capacity magazines would have lowered the casualty count.
Very questionable. The one fact we can ascertain from his use of a 100 round drum (assuming that was the case) was that he didn't know squat about high capacity magazines. He went for the cool factor rather than the efficiency factor. Anyone who's ever actually used those (with non-military weapons), knows that they jam pretty consistently if you're foolish enough to actually put more than about 60-70% of the magazine capacity worth of bullets in them. Which appears to be exactly what happened to him and likely prevented the death tool from being more like 100+
If he'd really wanted to just kill a ton of people rather than fulfill an image-fantasy of himself he'd have brought a number of lower capacity magazines and reloaded.
Fact: The expiration of the Assault Weapons ban in 2004 is the only reason he could buy an AR-15 assault rifle.
Um... To the degree that mattered though. The problem with that ban (as I argued waaaaay back in the day) was that it didn't actually define what an assault weapon was (not surprising when you consider what they were trying to do). Thus, they just banned a list of weapons by name. Predictably, the manufacturers just sold the exact same guns (with perhaps minor cosmetic changes) under a different name. The law was allowed to expire because it was silly and useless.
Um... But even if somehow magically we passed a ban that made it impossible for him to obtain any sort of firearm with which he could possibly kill a bunch of people in a crowded theater (basically impossible unless you repeal the 2nd amendment), he clearly had the knowledge and access to materials to just make bombs instead. Explain to me how that would have lowered the death count.
Fact: Liberals did nothing about either of the above after Giffords was shot, no need to worry they might do something now.
Fact: You are a turd.
Irrelevant considering "the above" are just plain wrong from start to finish.