I agree with you on the identity of the two witnesses in Revelation.
With regard to the "appointed once to die" I agree with Ready2Go on the source (Hebrews 9:27).
In addition to that are the tribulation rapture passages. I am of the pre-trib rapture belief. There are others who are of the mid-trib or post-trib and perhaps some who expect no rapture at all.
Following are tidbits selected from some of my personal favorite pre-trib passages. Lurkers may want to read the passages before and following each of these to get the full meaning to decide for themselves:
Then we which are alive [and] remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord. I Thess 4:17
And while they went to buy, the bridegroom came; and they that were ready went in with him to the marriage: and the door was shut. Matthew 25:10
Then shall two be in the field; the one shall be taken, and the other left. Matthew 24:40
Because thou hast kept the word of my patience, I also will keep thee from the hour of temptation, which shall come upon all the world, to try them that dwell upon the earth. Revelation 3:10
For God hath not appointed us to wrath, but to obtain salvation by our Lord Jesus Christ, - I Thess 5:9
If you want a good view, climb Mt Zion!
Isaiah 2:3
Renew your mind...
Revelation 11
3 And I will give power to my two witnesses, and they will prophesy one thousand two hundred and sixty days, clothed in sackcloth."
4 These are the two olive trees and the two lampstands standing before the God of the earth. 5 And if anyone wants to harm them, fire proceeds from their mouth and devours their enemies. And if anyone wants to harm them, he must be killed in this manner. 6 These have power to shut heaven, so that no rain falls in the days of their prophecy; and they have power over waters to turn them to blood, and to strike the earth with all plagues, as often as they desire.
7 When they finish their testimony, the beast that ascends out of the bottomless pit will make war against them, overcome them, and kill them. 8 And their dead bodies will lie in the street of the great city which spiritually is called Sodom and Egypt, where also our Lord was crucified. 9 Then those from the peoples, tribes, tongues, and nations will see their dead bodies three-and-a-half days, and not allow their dead bodies to be put into graves. 10 And those who dwell on the earth will rejoice over them, make merry, and send gifts to one another, because these two prophets tormented those who dwell on the earth.
The two witnesses are Jews and Christians.
War
And if anyone wants to harm them, fire proceeds from their mouth and devours their enemies
Three-and-a-half days... are the three and a half years of great tribulation.
And the sod level goes on and on and on and....