I studied it extensively maybe 30 years ago, even using the original Hebrew and Greek. It takes a lot of stretching and straining, and misinterpreting scriptures that had already happened in the distant past and projecting them into the future. There are various beliefs about the Rapture (that word is not in the Bible) with some believing in a pretribulation Rapture (Jesus comes in the clouds to snatch away the believing Christians before the bad time starts) midtribulation, and post-tribulation Rapture. The complexities do not end there. Christian Biblical prophecy is not simple and many people are making big money off of it nowadays.
The talk about a temple deal with the belief that a 3rd Temple will be built at the sight of Solomon's Temple (the Wailing Wall is the outer wall of that temple). The problem is that the 2nd most holy Muslim shrine, the Dome of the Rock (see:
http://witcombe.sbc.edu/sacredplaces/domeofrock.html) is at that place, which makes a new Temple problematic. Many Christians who believe in the Rapture and the prophecies they believe that will go with it have given a lot of money to see the temple rebuilt.
There are many Christians whose love of Israel has nothing to do specifically with the Rapture, but because of verses like Genesis 12:3 "And I will bless them that bless thee, and curse him that curseth thee: and in thee shall all families of the earth be blessed", which they apply to the nation of Israel or Psalm 122:6 "Pray for the peace of Jerusalem: they shall prosper that love thee." So the view that Christians love Israel primarily because of the Rapture is a simplistic view.
After studying the theory of the Rapture I believe it to be convoluted and many scriptures need to be tortured and misinterpreted to make it work. For those who believe in the Rapture I do not believe they delight in seeing Israel destroyed (for the most part), but they believe these things are a part of prophecy and will happen whether they want them to or not. You may disagree with them, but it does help to understand where they are coming from.
I do not believe in the theory of the Rapture and I no longer even consider myself a Christian (an agnostic at best). When it is said, "i really don't understand any of this", one might read that as saying you are ignorant about it. It is probably best to avoid extensive comment about things you do not know a lot about. A Christian who says crazy things is no more representative of all Christians than a Democrat who says crazy things is representative of all Democrats. There are many religions in the world and some of them are far out, weird, and incomprehensible to me and I might think those people are out of their fucking minds. Perhaps they are, perhaps I am, but perhaps I don't know enough about them or their religion and perhaps I should not paint with such a broad brush. That being said, the world would be ever so much a better place if everyone just believed what I believe and agree with all I say. Yes, it would be better. Not likely though.