1. Yes, He has a body of flesh and bone.
How does that square with John 4:24 — “God is spirit”?
This is the Greek:
πνεῦμα ὁ θεός, καὶ τοὺς προσκυνοῦντας αὐτὸν ἐν πνεύματι καὶ ἀληθείᾳ δεῖ προσκυνεῖν
The phrase, often translated, “God is spirit” is in bold. In Greek grammar, this is a qualitative predicate nominative, which deals with, not composition, but one's qualities.
Furthermore, a question that is begged is that “spirit” is immaterial. However, many early Christians believed that “spirit” was material (e.g., Origen, On First Principles, Preface 9 and Tertullian, Against Praxaes, 7), something consistent with LDS theology (D&C 131:7).
This verse is taking about God's accessibility not His composition.
2. If you read the entire King Follett Discourse, then you would know the Father received a body in the same way as the Son, yet we and you still think the Son is Divine before and after receiving His body. How does that fit Isaiah 43:10 — “Before me no god was formed, nor shall there be any after me”?
That is Isaiah writing about God in a similar way that other nations would talk about their gods. It is a statement of incomparability. This was a statement against idols not against a plurality of gods which you can find in the Old Testament, Psalms 82.
3. Joseph Smith talked about the Father having a Father, but that's really just a holy mystery. Isaiah 44:6 — “I am the first and I am the last; besides me there is no God”?
Isaiah’s repeated statements (“beside me there is no God,” etc.) assert Yahweh’s absolute supremacy and exclusive claim to Israel’s worship among other real divine beings in a heavenly council (Psalms 82, Job 1, Jer. 23:18, Deut. 32:8-9), rather than denying the existence of any other gods or the possibility of human exaltation.
4. Not only did they exist, but we all existed as Spirit children of Heavenly Father. Jesus Christ created the earth under the direction of Heavenly Father. In your theology, God created Satan exnihilo having a full knowledge that Satan would rebel against Him and receive eternal torment.
5. No. The idea of creatio exnihilo didn't come about until the late second century AD. Genesis 1:1, this is an introductory clause and many Bible scholars agree it should read , When Good began to create the heaven and the earth. Hebrews 11:3 κατηρτισθαι means to fashion or to order. (Benjamin Rojas Yauri, Hebrews’ Cosmogonic Presuppositions: Its First-Century Philosophical Context).
6. John says that we can become the sons of God. John 1:12, 1 John 1:1-2. I've already answered the Isaiah 44 issue, but even Paul in Acts 19:29 says we are the same race, genos, as God. Peter says we can partake in the divine nature. Paul focuses on deification immensely in his writings:
Romans 8:17 — Co-heirs who co-suffer and co-glorify with Christ (kinship and shared rule).
Romans 8:32 — Heirs of "all things" (cosmic rule/power).
1 Corinthians 6:2–3 — Saints judging the world and angels (eschatological lordship/rule).
Galatians 2:19–20 — "Christ lives in me" and co-crucifixion (union/identification).
Romans 6:1–11 — Dying and rising with Christ (participation in his acts).
Other supporting texts: Rom 8:15–16 (sonship), 1 Cor 15:22, 49 (as above), 2 Cor 4:16–17, Phil 2:6–11 (Christ's divine status), etc.
7. Yes, this is most plain in that there were no more 12 Apostles after John leaves and how none of the Creedal churches can produce new scripture.
Matt 16:18 is talking about the ekklesia, which would be understood my Jews as the assembly or gathering of people. Christ has the keys of death and hell. This
8. The Bible isn't infallible, but it is reliable, especially depending on the strength of the translation. 2 Timothy 3:16 is basically saying Scripture is given by inspiration, this applies to the Book of Mormon.
9. Faith is a verb in koine Greek. How can you have faith without action?
10. Did Christ gain a body?