Hey Joel!
Here’s my take.
καὶ ὃς ἀκούσας ἀνεκάγχασέ τε μάλα σαρδάνιον καὶ εἶπεν:
Why ὃς?
DEMONSTR. PRON., = οὗτος, ὅδε, this, that; also, he, she, it:
in later Gr. this usage remained in a few forms:
at the beginning of a clause, καὶ ὅς > and he, Hdt.7.18, X.Smp.1.15, Pl. Phd.118, Prt.310d ; καὶ ἥ and she, καὶ οἵ and they, Hdt.8.56,87, Pl. Smp.201e, X.An.7.6.4.
It is reminiscent of Latin “Qui”, which works in the same faction, except no “καί”.
Why τε?
I’d say it’s a simple connector. I don’t think it’s connected with the following καί (in a τε . . . καί construction), but I may be wrong.
Is σαρδάνιον an adjective (as I translated) or an adverb?
In your translation you seem to invent a word (“laugh”), a noun with which to pair your supposed adjective. It’s an adverb. The difference is slight, of course.
αὕτη 'κείνη ἡ εἰωθυῖα εἰρωνεία
αὕτη [ἐστιν] ἐκείνη ἡ εἰωθυῖα εἰρωνεία, is it not? Predicative, as you suggest.
ἐρωτᾷ
You don’t need the ἄν for conditional clauses. Besides, as you say, the only reason the main clauses are in the optative is because it’s indirect speech.
Hope this helps 