It seems I have a problem, and am only making it worse by following what I find online. I have a new Asus N550JV-D71 (not sure about the part after the dash, though I definitely know it includes 71). I decided to downgrade Windows 8 to 7, then dual boot Ubuntu 12.04 with it (there were issues with Windows 8, and I had a Windows 7 disk handy). It did work and, after installing Bumblebee in tty (because it wouldn't boot when it was first installed), it worked marvelously for a little less than a week. However, I restarted it last night and got the Could not write bytes: Broken pipes error. (I see it's a very common error, but I've looked at the majority of the suggested Similar Questions already.) I followed what I could find online, followed those instructions (making sure to not install any sort of graphics drivers other than what Bumblebee provides), and it just seems to go further and further downhill.

I'm afraid I didn't write the exact steps to get to this point (it was late by the time I gave up the night before), but it involved reinstalling lightdm, xorg (and xserver?), and Bumblebee. I then changed the Bumblebee.conf file so that Device=nvidia. I'm pretty new to Linux in general (I've used it since 10.04, but I hadn't had issues up until this computer, so it let me stay a newbie), so I'm not exactly sure what log files to look at to find the errors to look up. However, I did look at lshw and noticed that displays was marked as unassigned. Also, if I try to start lightdm using the command line, it always stops at Stopping Mount network filesystems. I should note that there isn't an xorg.conf file, and no .Xauthority.

I would really, really prefer not to reinstall 12.04 if possible. I managed to get grub to display only a short time ago, and I can't boot to the dvd drive unless I go into the BIOS settings and manually change the boot order (that was an issue from the beginning, before the Ubuntu install), and getting into those settings often means rebooting several times due to the fact that the window to get to it is extremely small. I have most of what I need backed up, however, in case it does get to that point. If I really have to, I can just use the latest Ubuntu version instead of the LTS, but the reason I chose 12.04 in the first place is because I need something stable-ish, and Windows isn't suitable to what I need to do.

I should note that the reason I restarted last night in the first place was that it wasn't charging the battery, and the wifi kept on going out.

Hardware:
Nvidia GeForce GT 750M
Intel HD graphics 4600