I'll just point out few quibbles in the power descriptions.
There's an "Etheralness (Su)" typo at the start of Etherealness.
Improved Grab has "To use this ability, an opinicus must hit with
its both claw attacks". Either make it "both its claw attacks" or "a claw attack". Don't much mind which.
Also, the "Non Psionic Opinicus" has a fair bit of work to do to convert the SLAs to PLAs. Not to mention the "Medium Magical Beast (Psionic)" looks a bit odd - Isn't the whole point is to remove the (Psionic) subtype!
13 HD appeals.
Add +4 to all mental ability scores?
13 Hit Dice is good.
I'd increase some of the physical stats too.
We don't want to make them better than out Greater Lammasu conversion.
Greater Lammasu: Str 27, Dex 12, Con 17, Int 20, Wis 21, Cha 18
I don't like the idea of them being wiser and tougher than Greater Lammasu, so how about putting a bigger increase in Dexterity and Intelligence and less in Wisdom, while leaving Con unchanged?
Greater Opinicus: Str 17, Dex 19, Con 16, Int 19, Wis 20, Cha 18