Yes, that is what the Book says, nobody doubts that. However, that passage you try to use as a proof actually refutes any pre-tribulation rapture as it clearly refers to the 2nd Coming of Christ, which happens at the end of the tribulation.
No, not really. 2 Thessalonians 2:6-8:
6 And now ye know what withholdeth that he might be revealed in his time.
7 For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.
8 And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming:
In this case, "letteth" is referring to a hinderance (Isaiah 43:13, Romans 1:3) - there are few things that are currently 'hindering' the anti-Christ to be revealed, including government, the Church and the Holy Spirit. Given that this all occurs AFTER "Revised Rome" has been formed, government would not then 'hinder' the coming of the anti-Christ. The Holy Spirit will not abandon the earth, and will be with folks during the tribulation (Joel 2:28-32; Acts 2:17-21; Zech. 12:10; Rev. 7:9-17). The only thing holding back the anti-Christ is the Church, which will be taken up to meet the Lord in the air (notice He is not actually returning to earth at this time). This clears the way for the anti-christ to be revealed and the days of the tribulation to begin.