1 Me its hard to say how long it took because I did other stuff as well, but would hazard a guess at 4 hrs, I hired a right angle drill from kennards and have my own easy outs.
2 Depends on the hourly rate if you have all the parts.
3 Repco had to order them (3 days) $70 through a mechanic mate.
4 There are 12, I replaced them all even though some were good, if one has snapped (2 in my case) the others are stressed but if you want them I have em still.
5 I dont know but mine was cracked and I replaced it with a standard one, if I had had the time I could of got one for $30, have a look at my thread in the Qld for sale (WTB manifold)