Flat_Accent:
In connection with Revelation 1:8 and 22:12, I thought you might find these comments from the Baker Exegetical Commentary on Revelation. (The author is Grant R. Osborne) This is an academic commentary on Revelation, rather extensive, about <900 pages.
Revelation 1:8
"I am the Alpha and the Omega," says the Lord God, "who is, and who was, and who is to come, the Almighty."
In the text on page 71:"Of the three uses of the title in Revelation, two refer to God (1:8; 21:6) and one to Christ (22:13; though see 1:17, where Jesus is "the first and the last") From the start the unity of the Father and the Son is stressed. Here God is "the Alpha and Omega" and Jesus is "the first and the last." (1:17). In 21:6 God is "Alpha and Omega" and in 22:13 Jesus is "Alpha and Omega (see Bauckham 1993a: 54-58).
There is a footnote concerning 1:8 on page 71 that says: "While some (Walvoord 1996:40; perhaps Caird 1996:19) have argued that this is Christ rather than the Father (due to the centrality of Christ in the context), the use of OT designations for God ("LORD God of Hosts" was a favorite OT title) and the repetition of the title for God in v.4 make it more likely this refers to God the Father."
In connection with "Lord God" in 1:8: "It should be connected with "I am" ["who is" in 1:8] to stress God as the Yahweh of the OT."
Revelation 22:12
"Look, I am coming soon! My reward is with me, and I will give to each person according to what they have done. 13 I am the Alpha and the Omega, the First and the Last, the Beginning and the End.
Under the sub-title "Identity of the One Coming (22:13) on pages 788-9 it says: "This is the last of the [the Alpha and the Omega] passages, and fittingly all three types of this saying are found here (the only place in [Revelation] where this occurs). Moreover, this completes the attribution of the titles to God and Christ in a kind of ABAB order: in 1:8 it refers to God ("Alpha and Omega"), and in 1:17 and 2:8 it applies to Christ ("the First and the Last"). Then in 21:6 it refers to God ("Alpha and Omega, the Beginning and the End") and in 22:13 to Christ ("Alpha and Omega, the First and the Last, the Beginning and the End"). The titles refer to the sovereignty of God and Christ over history. They control the beginning of creation and its end, and therefore they control every aspect of history in between. Since this is the only passage to contain all three titles, it has the greatest emphasis of them all on the all-embracing power of Christ over human history. These are the perfect titles to occur between the emphasis on Christ's coming as judge in 22:12 and the warnings to the believers and the unregenerate in 22:14-15. Christ is sovereign over all and therefore the one who has authority over the destiny of everyone."
Concerning both these particular verses, there are no debates about the validity/reading of the Greek text.
As you can see, this expositor has no problem applying the title to both God and Christ. Hope this is some use.
Take Care