a) maybe they are, or intend to, or indeed intend to move against their parent company, Gawker media.

b) Chen was the last person who had possession of the device; when Apple's general counsel demanded its return, the Gizmodo editor directed him to contact Chen directly.

It might be more appropriate to wonder why Chen was left to handle the situation on his own, rather than the return to Apple being handled by Giz/Gawker's legal counsel or legal representative.

Because he is the one who (allegedly) received stolen property.

Because you cannot make criminal case against company. (I assume that this is the case even in US. And from practical standpoint it makes sense: how would you send company to jail?)