Do the Orthodox believe all parts of the Bible are God-inspired, but not necessarily God-endorsed?
The terminology is obscure, but it is an interesting question.
(1) Was Paul inspired when he said that the time was short (I Cor. 7.29)? For he was surely wrong (on the naive reading) about the immediacy of the Lord's return.
(2) Was Paul inspired when he said that he had no command from the Lord and so offered his judgment instead (I Cor. 7.25) about unmarried young ladies? For he explicitly denied what we commonly imagine the vital portion of his authority--commandment from the Lord.
(3) Did Jude (14-15) cite I Enoch 1.9 to the effect that Enoch proved inspired or was Jude inspired and this verse handy? For I Enoch is generally regarded as uninspired.
(4) If I read and reflect on the Apostolic Fathers, I note that a good deal is said without NT (or OT) citation. What were they doing in those early days without "inscripturated" Bibles? For they had no inspired Scriptures (that we know of) at first.
(5) In particular, consider this passage from Hermas:
"You do not know," he says, "how to fast unto the Lord: this useless fasting which you observe to HIm is of no value." "Why, sir," I answered, "do you say this?" "I say to you," he continued, "that the fasting which you think you observe is not a fasting. But I will teach you what is a full and acceptable fasting to the Lord. Listen," he continued: "God does not desire such an empty fasting? For fasting to God in this way you will do nothing for a righteous life; but offer to God a fasting of the following kind: Do no evil in your life, and serve the Lord with a pure heart: keep His commandments, walking in His precepts, and let no evil desire arise in your heart; and believe in God. If you do these things, and fear Him, and abstain from every evil thing, you will live unto God; and if you do these things, you will keep a great fast, and one acceptable before God.
This sort of text, like others in the Fathers, the services and prayerbooks, smite the very heart. If we have a criterion for inspiration, such as profitable for doctrine etc., then it is difficult for me to suppose that the inspiration in these lines by Hermas is inferior to anything else that is now dubbed as inspired, to wit, the OT and the NT.
In conclusion, I suppose that Scripture is lumpy, since I conceive that it is possible for Paul to err, for profitable instruction to masquerade as history (Genesis, e.g.) and so forth. However, this lumpiness is not a reason for consternation, since we conceive of the Bible as integral to worship and not as the basis of our Faith. We worshipped God before the Bible was compiled and approved and we would worship God without it being compiled and approved. When I read Mother Gavrilia, I believe that she was truly inspired by God, yet that does not make her words canonical. What matters is that the Holy Spirit always comforts us and instructs us, whether through the Bible, the Fathers, the Liturgies, the prayerbooks etc. The canonization of the Scriptures is in a sense a convenience for the faithful.