Read Ezekiel chapters 8-9. Biggest clue in there as to what the mark of the beast is about.
The mark of the beast has been worn by occultists for thousands of years. It is the satanic symbol, not the tech embedded into it that makes it evil. Everyone has seen at least one version of it. It is the symbol of the occultic sun.
The rebuilt temple is meant to be taken literally. It's not just the Jews that want the temple in Jerusalem rebuilt...
If you take the language literally the temple mentioned in 2 Thess 2:4 is the New Testament Temple. The word naos refers to the actual sanctuary of God (unlike the word hieron, which refers to the temple structure / buildings) and the word naos is not used again in reference to the temple in Jerusalem after the three verses in the synoptic gospels telling us about the tearing of the veil in the sanctuary of God of the temple in Jerusalem when Jesus died on the cross.
Acts' multiple references to the temple in Jerusalem use the word hieron, never the word naos. When Acts records the Jewish leaders accusing Paul of defiling "this holy place" (meaning the temple in Jerusalem), the words used are hagios topos (holy place).
In Acts we are told twice by the apostles of Christ that God does not dwell in a naos (God's sanctuary) made with (human) hands.
When Paul mentioned the temple in Jerusalem in his epistles, he used the word hieron. When he refers to the bodies of individual saints as the Temple of of God and the church as the Temple of God, he uses the word naos each time. So why would he have used the word naos in 2 Thess 2:4 if he was talking about a structure to be built in Jerusalem that many will call "the Temple of God"?
That structure will be a hieron, not the sanctuary (naos) of God. Even the inner sanctuary of that temple will be the hieron, not the sanctuary of God (naos).
Every reference to God's (heavenly) Temple in the Revelation uses the word naos.
The only verse that many choose to dispute is Revelation 11:1-2, which uses the word naos - but the holy city is mentioned in Revelation 11:2 and the Revelation calls New Jerusalem the holy city three other times, but never calls the other cities mentioned in the Revelation "the holy city, which are
Babylon the Great
The city spiritually called Sodom and Egypt where our Lord was cricified
The cities of the nations that fell when the 7th bowl was poured out.
Obviously the Revelation does not call the above cities the holy city - but it calls New Jerusalem or Mount Zion the Holy City three other times, aside from Revelation 11:2.
So because the temple in Revelation 11:1-2 is linked to the holy city in the verses, and the word naos is used in reference to the temple, it's way more likely that Revelation 11:1-2's temple is referring to the same temple mentioned in Revelation 13 that will be blasphemed by the beast - who Revelation 13:7 tells us will go to war against the saints and overcome them.
So if you indeed do choose to take the language literally (as you claim to) , then the temple mentioned in 2 Thess 2:4 and in Revelation 11:1-2 is the New Testament Temple - because the New Testament was not written in English - it was written in Greek, which maintains a consistent distinction between the naos (actual sanctuary of God) and hieron - a temple structure.
In our day hieron would be the church building. The naos (sanctuary of God) is only present when the saints are gathered in it, because where two or three are gathered together in Jesus' name, He is there in their midst.