These are just my opinions based on my interpretations:
1. Yes. The 144,000 in Revelation 14 sing a song that only they know. This is a reference to the Old Testament musicians that were given prophecy through song while they worshiped in the temple. Another reference is the Two Witnesses of Revelation 11, which draws symbolism from Zechariah 4's two witnesses commissioned by God to rebuild the temple. Reminiscent of Zechariah 2, John is told in Revelation 11 to measure the temple, the altar, and those worshiping there. Another reference is Daniel 9:27, which says that an abomination that causes desolation would come on a wing of the temple. Jesus quoted this when he spoke of the abomination of desolation standing where it ought not. Paul shattered all doubt when he said that the man of sin would sit on a throne in the temple and show himself to be divine. Finally, the temple could be a simple tabernacle, so long as it follows the biblical design. The red heifers are needed to purify the temple. BUT, the location of the temple matters. That is where the Dome of the Rock is.
2. I don't think Israel is scared of the Muslim countries. I think they genuinely want peace. If they could have normalization with Saudi Arabia, Egypt, UAE, Jordan, Kuwait, Morocco, and more, that would be optimal. You spend less money on warfare and repairs while making more money on trading goods. The Abraham Accords in 2020 was a very good start. The Al Aqsa Flood occurred while Israel and Saudi Arabia were on the verge of normalization. This left Saudi's competitor with no other option but to attack. What has happened now is the Middle East is realigning. Everyone sees what Iran has done to Gaza, Lebanon, Syria, Yemen, and Iraq. The veil has been removed and the world is choosing sides. This benefits Israel because they now have allies. Jordan won't let Iran use their air space. Egypt won't accept refugees. Saudi Arabia still seeks normalization with Israel. The United States are fully on board with protecting Israel. Iran knows this now.
Israel has committed to fighting on all fronts. They are chasing Hamas to the Egyptian border, eliminating jihadists in West Bank, targeting Hezbollah in Lebanon and Syria, and attacking military leaders as far as Iran. Israel isn't scared. Exact opposite. They now have the leverage that must provoke attack. Jerusalem is the hook that brings them back so God can show His power and glory to the world while simultaneously eliminating Israel's enemies. Think of the Al Aqsa Flood as the serpent spewing a river so as to sweep Zion away with a flood (Revelation 12:15). When we see Turkey commit to military action against Israel (Ezekiel 38-39, Joel 2, Psalm 83, Isaiah 37:21-35, Micah 5), we will know that God is about to work wonders so terrifying it will make the ears itch on anyone who hears of it. Then Daniel 9's seventieth week of years will begin.