I am trasnlating those sentences from Historia Ecclesiastica of Bede - Book 2, paragraph about Pope Gregory the Great:
[1] Responsum est quod Angli vocarentur. At ille, “Bene,” inquit, "nam et angelicam habent faciem et tales angelorum in caelis decet esse coheredes.
[2] Quod habet nomen ipsa provincia de qua isti sunt adlati?
*** The “Quod” [1] is used to mark a indirect statement, it is equivalent as “That” in Modern English, right?
The “Quod” [2] is a interrogative Pronoun, right?
So
Responsum est “quod” Angli vocarentur = The answer is “that” they are called Angli
“Quod” habet nomen ipsa provincia de qua isti sunt adlati? = he keeps [asking] (habet) “what” name of the particular province from that they are brought to here?
2 seems like you made a big, unnecessary (and false) circle. Quod isn’t really an interrogative pronoun, it is an interrogative determinant agreeing with ‘nomen’ (which is neutral), here in the accusative because it is the object of Habet. «What name does the province have, from which they were brought?»; more fluidly «What’s the name of the province» etc.
Totally right, the order is always a challenge for me, although we know there’s no fixed order for Latin, however, is there any guiding principle except: commas and preposition?
In #1, responsum est is probably perfect passive in an impersonal construction: “it was answered” or “someone answered.” It’s interesting that the verb vocarentur is subjunctive. In post-classical Latin, when quod became the marker for indirect speech, the indicative would have been used here.
Not entirely true. The use of the subjunctive becomes somewhat erratic in Late/Ecclesiastical Latin. It’s not used where it should be, and it is used where it shouldn’t be, and it depends upon the author. There are basically three possible constructions for indirect speech in post-classical Latin: Acc/Inf (rarest), quia/quod + subj., quia/quod + ind. The subjunctive with this construction is quite common, although I have no idea how it compares to the construction with the indicative. The classical Acc/Inf construction, however, is almost non-existent.