Ubuntu – My average laptop temperature is 75C. Is it Normal

Have a read through this as it it's very complete

http://wiki.cchtml.com/index.php/Ubuntu_Raring_Installation_Guide

You should be able to get everything working by carefully following the instructions. Though I'd follow all of the un-installation steps first to get your install back to the open source drivers and in a working state before trying again.

Sound probably won't work though as I can't get any audio at all right now and the 'sound card' in my GPU is not detected. Not very happy right now. Should have stuck with 12.10 which worked with no issues.

The display of the graphics card name in System Settings often does not work (just search askubuntu, there are dozens of questions about it and the answer is always the same...). I wouldn't worry about it and only trust other tools to find out which graphics driver is in use.

Your laptop obviously has a recent Intel CPU, which includes a graphics unit. This is the reason, an Intel graphics card is shown in lspci.

Your xorg.conf hints that atm you are using fglrx, and it seems to be working. To see, if the driver is really active, simply try to run fglrxinfo. Another tool that you might take a look at is amdcccle, the catalyst control center. It will give you a lot of details (if fglrx is installed).

Since you installed the driver from the AMD website, "additional drivers" will not show any driver in its list as active (since you didn't use official driver packages for Ubuntu, but the download from the AMD website).

I don't know about your laptop specifically, but you might find this guide useful: Installing Catalyst with Intel/AMD hybrid graphics

Oh, and btw, the preferred way to install the driver downloaded from the AMD website would be to make distribution specific packages and then to install those. By this, you can ensure that it stays working when you get Kernel updates. If you simply install it, it might be, that you have to reinstall it every time, a Kernel update is installed.