2. try apparmour
4. never used one so I'm not much help there
5.anyway linux desktop except unity, or gnome3, however since aero is a kde 4 wonna be, u may what to try that, if thats not to your liking, then cinnamon and mate or xfce are all good.
6.should be taken care of provided you install install gcc and g++, also if you looking for a ide, try kdevelop or codeblocks
7.gnome is integrated with epiphany, kde with konqorer, both more secure then IE, I personally however recommend firefox.
8.vlc will play anything you throw at it and is more designed for video, for music however if you use kde then amarok is where its at, anything try banshee.
9.your install of mint 13 should have a firewall built in, gufw
10. really not neccesary, infecting a linux machine is much harder then a windows machine, if you insist though then you can try avg, avast, bitdefender or clamtk, I use clam.
If you install mint already then i suggest waiting till 13 comes out, just 12 or sort of a odd ball release, and 13 will be out on the 25th