Where are these cities?
Malbim: They are in the north of Eretz Yisrael.
Is this the same Rechov as (Bamidbar 13:21) "Rechov l'Vo Chamas" mentioned regarding the Meraglim?
Bi'ur ha'Gra: Yes. Chamas is in Chutz la'Aretz. It is mentioned to specify the Rechov near Chamas, in the northwest corner. There is another Rechov (verse 30).
Is Tzidon in Asher?
Bi'ur ha'Gra: It is in Asher, for it says "Asher Lo Horish