8, 4, 4

σαφηνίζεσθαι δὲ ὡς ἕκαστον ἐτίμα διὰ τοῦτο ἐδόκει αὐτῷ ἀγαθὸν εἶναι
What is the subjest of σαφηνίζεσθαι

Looks like it is Γαδάτας, previously introduced.

I don’t think so

Meseemeth the subject of σαφηνίζεσθαι to be ὡς ἕκαστον ἐτίμα

ay, but to be more specific ἕκαστον

No, the whole phrase: it seemed good to him to be made clear how he esteemed each etc.

Yes, the subject of the sentence is the infinitival phrase σαφηνίζεσθαι ὡς ἕκαστον ἐτίμα (σαφηνίζεσθαι passive), and the subject of σαφηνίζεσθαι is the clause ὡς ἕκαστον ἐτίμα. May seem crazy but that’s traditional grammar for you.

σαφηνίζεσθαι stands up front, i.e. it has salience. The next sentence, when it comes, repeats the same verb but now in the active: καὶ ὁ Κῦρος δὲ οὕτως ἐσαφήνιζε μὲν τοὺς κρατιστεύοντας παρ᾽ ἑαυτῷ, … (the μέν to be picked up by ου μέντοι …).