I feel like Christ lays out everything perfectly in Matthew 24, Mark 13 and Luke 21. When he says he comes "immediately" after the tribulation I choose to believe him. He has foretold us "all" things. If he was coming before the tribulation, he would have certainly told us. Even the word "taken" in Matthew 24:40 which started the whole "Left Behind" thing is not the same meaning as the word "taken" in Matthew 9:15 when Christ talks about the bridegroom being taken. Those are two different Greek words and the word "taken" in Matthew 24:40 is paralambano and it means, to receive near, associate oneself with. The word taken in Matthew 9:15 is apairo, it actually mean's removed, lift off....
I Thessalonians 4:16 "For the Lord himself shall descend from heaven with a shout, with a voice of the archangel, and with the trump of God: and the dead in Christ shall rise first;
We know by Revelation that Christ returns at the 7th. So that would be the trump of God.
The problem with a pretrib rapture with 1st Thess 4:17 is that some people stop there. But the manuscripts had no chapters and Paul is still continuing on the same subject so we need to read these completely as to not lose context,
I Thessalonians 4:17 "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 Thessalonians 5:1 "But of the times and the seasons, brethren, ye have no need that I write unto you."
I Thessalonians 5:2 "For yourselves know perfectly that the day of the Lord so cometh as a thief in the night.
So right there you see that Paul names the event of 4:17 "the day of the Lord". The day of the Lord has been talked about all throughout the bible.
Paul had to write a 2nd letter to the Thessalonians though because they too, were confused on the timing. He tells them to not even be confused even by their first letter that the day of Christ/day of the Lord (same "day", subject hasn't changed) was at hand. He says "that day shall not happen until a great falling away and the son of perdition sits on the throne proclaiming to be God.
II Thessalonians 2:1 "Now we beseech you, brethren, by the coming of our Lord Jesus Christ, and by our gathering together unto him,"
II Thessalonians 2:2 "That ye be not soon shaken in mind, or be troubled, neither by spirit, nor by word, nor by letter as from us, as that the day of Christ is at hand."
II Thessalonians 2:3 "Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition;"
Both Christ and Paul give out strict warnings not to be deceived on this subject. If the warnings were not important, they would not have given them.
Paul says, I will tell you a mystery, we shall not all sleep, but we shall all be changed at the "last' trump in 1st Cor 15:51 and 52.
I Corinthians 15:51 "Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed,"
I Corinthians 15:52 "In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed."
Last in the Greek is the "fartherest out" That would be the 7th trump when aligned up with the trumps in Revelation. And this also lines up with 1st Thess 4:16. And we have to align those up with Revelation because that is the subject, when Christ returns. He returns at the 7th. Antichrist/Satan will be here at the 6th. As you said, there are no mentions of trumps in the NT other than the ones in Revelation. That's because they are talking about the 7th and last trump.
Christ says those that endure to the end, the same shall be saved. And Paul says we must have the full gospel armour on to stand in that evil day. I don't think they can make it any clearer that Christians will be here during the tribulation.
Some will tell you that the Holy Spirit will be removed. But Christ himself taught that some will be delivered up at that time for a testimony (same as Revelation 12) and not to premeditate but that it will be the Holy Spirit that speaks through them. Also in Revelation 12, we note that it's Michael that's fighting with Satan and after this battle is when Satan and his angels are thrown out. That is future.
Acts 3:21 says Heaven must receive Christ until the restitution of all things.
Acts 3:21 "Whom the heaven must receive unto the times of restitution of all things, which God hath spoken by the mouth of all His holy prophets since the world began."
Revelation 1:7 "Behold, he cometh with clouds; and every eye shall see him, and they also which pierced him: and all kindreds of the earth shall wail because of Him. Even so, A-men."
I used to believe in a rapture (taught that in the church I grew up in) but I don't find it biblical at all.