This is not actually true. Three of my five level 50 characters, I've done Class, Planet, and Side quests, completely skipping Heroics, PVP, Space, and only doing the Esseles/Black Talon flashpoints. I have reached Corellia at no lower a level then 48, and was always at least a level or two ahead of the content I was playing.

Windows 8 is built on top of the Windows 7 core. Thus, anything that works on Windows 7 should work seamlessly with Windows 8. While it does not guarantee it, I can't think of anything in SWTOR that would cause it to fail if changing the OS.

I remember that too. I also remember how I won. The key was to stay real far back, send your companion to attack him, and then switch your companion to passive mode right after the first attack. Jadus would follow your companion down the stairs, and once Jadus was off the platform, there was no Line of Sight issue. After that, you could just use your method of choice for fighting him (I dodged around computer consoles while taking pot shots at him to constantly break his line of sight).