Animating objects as a group and individually

I've created a grid of around 80 individual text layers (each layer is a single letter) and first, I want to animate their opacity as a group, then INDIVIDUALLY animate their opacity (again) and color.  How do I do this?

Also, while I'm asking, I have two simpler questions:

- is there a way to animate the color of multiple layers at once so I don't have to click on each individual layer and do it manually?

- how do I achieve a "swipe" opacity effect?  If this is not clear I can explain but I won't bother for now.