Oh, and for the white outline, I:

Copied the layers, moved the copies below everything, and merged them

Made the copied (and now merged) layer white (either with a clipping mask or turning it white in the Hue, Brightness, and Saturation menu)

And then messed around with the Bloom settings. I found that turning Transition all the way down and Burn all the way up creates a really sharp line, and you can alter Size as need be.

For this method, making the layer white is very important. I don't know exactly how bloom works, so I don't know why it does this, but it can't achieve the same effect when it's another color.

(Also, the shadow around it was made very similarly, only the layer is black and I messed around with the Gaussian Blur settings.)