Revelation 11
My take is that the two witnesses according to Zechariah 4 and being this is a world wide event as in all nations when they come to preach during the last 3 1/2 years are that of the Jews, (like the Disciples) who are to continue their commission to preach the Gospel to the lost sheep of Israel, Matthew 10:5-7 as Jews throughout the world have not yet accepted Jesus as Messiah. Paul on the other hand was called to preach the Gospel to the Gentiles, Acts 22:21, as well as the Gentiles who are called at this time to preach the Gospel in all nations only to the lost Gentiles.
"Last 3 1/2 years" doesn't add up. The Beast who ascends from the abyss kills them and then rules for 3.5 years:
5 And he was given a mouth speaking great things and blasphemies, and he was given authority to continue for forty-two months. (Rev. 13:5 NKJ)
As for your study, not bad. Just too wordy. You could have said the Holy Spirit is poured out on the church when these two showed up, that is what the symbolism means:
4 These are the two olive trees and the two lampstands standing before the God of the earth. (Rev. 11:4 NKJ)
11 Then I answered and said to him, "What are these two olive trees-- at the right of the lampstand and at its left?"
12 And I further answered and said to him, "What are these two olive branches that drip into the receptacles of the two gold pipes from which the golden oil drains?"
13 Then he answered me and said, "Do you not know what these are?" And I said, "No, my lord."
14 So he said, "These are the two anointed ones, who stand beside the Lord of the whole earth." (Zech. 4:11-14 NKJ)
The fire is fed by the oil from the two gold pipes. Baptism in fire, oil symbolizes the Holy Spirit. This is when the Joel's prophecy is fulfilled, in the end time and not Azuza Street:
16 "But this is what was spoken by the prophet Joel:
17 `And it shall come to pass in the last days, says God, That I will pour out of My Spirit on all flesh; Your sons and your daughters shall prophesy, Your young men shall see visions, Your old men shall dream dreams.
18 And on My menservants and on My maidservants I will pour out My Spirit in those days; And they shall prophesy.
19 I will show wonders in heaven above And signs in the earth beneath: Blood and fire and vapor of smoke.
20 The sun shall be turned into darkness, And the moon into blood, Before the coming of the great and awesome day of the LORD.
21 And it shall come to pass That whoever calls on the name of the LORD Shall be saved.'
(Acts 2:16-21 NKJ)
As we all know, the Day of the LORD didn't happen in the 1st century, therefore "this is what was spoken by the Prophet Joel" in prefigure of what will be in the end time, when wonders in heaven above and signs in earth beneath"... will occur as the book of Revelation reveals.