My confusion is growing. Your last pastebin says you a re running a 32bit OS. IMHO there is no way you can run 64bit programs...
Please correct me if I am wrong. And maybe upload another pastebin that shows you have 64bit Java installed. Make sure that your graphics drivers are up to date, and that you use the default textures.
Don't worry, your confusion is normal. My computer is haunted.
Went and looked in my system information and it says I'm on a x64-based PC system type. Pretty sure that means I'm on a 64 bit machine. If not, then -shrugs- the program froze when I tried to save it.
However, I can tell you, that I have absolutely run the 1.6.4 modpacks on this machine previously. And I have currently installed 64bit java, and FTB seems to be happy with it. (no message about my system running 32 bit java limiting it to 1.5 gig of ram anymore), but the problem persists. Let me go grab a new pastebin for you guys.
This one is from trying to run Horizons. If you guys want me to stick with a single mod, say it now, but since it is multiple mods exhibiting the same problem, I feel like it would give you a lot of red herrings. Considering that it is a normal thing for me to see Minecraft freeze on launch before finally pulling through.
http://pastebin.com/gCqsRHqi
By the way, seriously guys, this may be a problem with my computer (since it's haunted), but I only came here because the only change between running and no longer running was an update to the launcher. I honestly kinda hoped it would be a common problem with this update or something.