[alex partington] “The text fading in and out at the top and bottom”
Pre Comp your text. Then add a mask to the precomp. Then increase the feathering on the mask.
I say this alot Haha! After Effects has a particular render order: Source, Mask, Effect, Transformations (SMET). So when you precompose a layer, it is not like a group in photoshop. It changes the render order of your layers, turning into a source. So you need to precompose your layer and add a mask to the (newly created) precomp. However, all the “normal” animations you have already made will remain inside.
I hope that makes sense!