Actually Jesus returns twice...

[CrowCross]

EVERYONE!
If the first rapture is invisible and mid-trib, and the second rapture happens at the visible Second Coming, where does Paul get to call the first one a 'last trumpet' if there is another group being gathered later?

Well we know Paul didn't get the idea of trumpets from John...as 1 Thes is older and written before John wrote Revelation.
Perhaps the trumpets is in reference to a feats?

There's also trumpets of God and trumpets of Angels.

And where in Scripture are believers ever divided into two separate categories of 'Church' and 'Tribulation Saints' who get different salvation timelines?"

You got to distort scripture to fall in with that way of thinking

 

[CrowCross]

Why would you think that "he shall come to be glorified in his saints, and to be admired in all them that believe" (2 Thess 1:10) 7 years after the rapture? You think we will be gathered to Him at the rapture, but Jesus won't "be glorified in his saints, and to be admired in all them that believe" at that time?

Why do I think? The answer is because this verse doesn't show the way Jesus left. (remember Jesus returns at the rapture the way He left)

when the Lord Jesus is revealed from heaven with his mighty angels 8in flaming fire, inflicting vengeance on those who do not know God and on those who do not obey the gospel of our Lord Jesus. 9They will suffer the punishment of eternal destruction, away from the presence of the Lord and from the glory of his might, 10when he comes on that day to be glorified in his saints, and to be marveled at among all who have believed, because our testimony to you was believed

Jesus didn't leave in Acts 1 with flaming fire...