When creating photoshop graphics is the correct size for 16:9 video the 720x480 with 1.21 pixel ratio?

I build mine at 853x480 with a PAR of 1

That way geometrics ALWAYS work right

I build mine at 853x480 with a PAR of 1

That way geometrics ALWAYS work right
Yes, Final Cut assumes that pictures do have quadratic pixels and automatically squeezes them fit the pixel-size of the sequence. But yes, 720x480 would be the correct size if you would like to do it manually, but I don't know how to tell Final Cut, that your picture doesn't use quadratic pictures.