allwon empty magnetic eyeshadow makeup palette with 12pcs 26mm round metal pans

Q: Will Ulta magnetic eye shadows fit?

I think so! Any 12mm pan should fit.

Q: Does anyone know if this works for Colourpop eyeshadows?

Yes, for colourpop singles but not for the smaller pans that are typically in colourpop palettes.

Q: How do you get your name engraved on the case

I wasn't aware this was an option. I don't recall being asked during check out.

Q: Can the piece that holds the pans be removed to have an open palette? or is it fixed to the palette permanently?

It doesn't let me attach a picture to a response,but I think I included it in my review. There is a visible insert with a ridge space that runs around the inside perimeter. But whether or not you can completely pop it out is another question. I specifically bought this for single shadows in 26mm pans so it works perfectly for me the way it is designed. Check and see if my picture is attached to my review. Good luck.