It is a lot to do, I'll freely admit to it. However you are NOT ready to raid the instant you ding 70, you're just not. It might take you a week or two to get ready, that's typical. If you're no longer wearing greens, aren't using spell damage or ret gear, then you're more than likely alright to go. If you're planning on healing a raid (even if it is kara) when you're using greens, spell damage gear, or worse, ret gear, then you're likely going to get someone killed. The point to being prepared isn't to improve your performance, its to keep others from dieing.