From what I have read, the return from exile in Babylon saw the Jews split between the stricter, cultic Zionists and those who spiritualised the religion (perhaps that has carried on and therefore explains the attitude of your friends).
Those that did return to Judah and rebuilt the temple (see the books of Ezra, Nehemiah, Haggai and Zechariah) made a whole-hearted effort but it bore no resemblance to the opulent structure that Solomon created.
When Herod the Great appeared on the scene, he went about an upgrading project which saw it restored to something closer to its former stature.
I've read some stuff about the doubts over the exodus too. My conclusion was that a lack of archaeological evidence for an event is not evidence that it didnt happen. Also, the exodus was where the law was given to Moses and the religious expectations of the nation were made known. The people could all trace back forefathers to this time, and so if this was a myth, then a) everyone would know about it, and b) why would they all make life so difficult for themselves by adhering to a system of worship which was so difficult and costly?
That said, I'm probably unaware of the whole argument and, to be fair, this is probably getting a bit dull for the gag-hunters
