The second picture has been confirmed to be Noctis' father. And I assume the last one is too. And if I had to guess I'd say the first picture is Noctis' uncle or some other relative who wants the throne. I know, it's a bit cliched, but there's a part when Noctis' dad says "you'll never be King" and I belive Nomura said that he isn't speaking to Noctis, so it may be him. He is pointing a gun at him so it is plausible.