Half of the Espers on your list appear as Lucavi demons in FFT, as was mentioned in passing, and they retain similar appearances to their FFT counterparts. Zodiark is the only Esper that appears as a summon instead of the boss. The other Espers such as Mateus don't appear directly, although the Zodiac stones that can summon them do. Turns out if the human that posseses the stone is pure of heart, the Lucavi doesn't take them over.

I'm not saying that some of these Espers aren't references to previous FF villains (Exodus is clearly X-Death as you suggested), but many of them are simply villains from the same game.