2003 BMW 540i Repair costs

After having my engine temp spike recently in traffic, I took the car to a BMW dealer who said I needed a new fan clutch and thermostat. The repair bill was $925 to which I had him replace engine belts for another $200. Car was in the shop for 2.5 hours. He also said I was leaking coolant in the valley pan, leaking oil from valve cover gaskets and the water pump had some play. Estimate to replace these items was $2,000 which was mostly labor he said. My questions are 1) are these costs reasonable and 2) should I use this opportunity to replace other things such as rear cross over gaskets, cooling pipe o-rings, intake gaskets,oil separater, plugs & boots? anything else? And if so, what should all these items cost in terms of parts and labor. thanks