For question 3, depends on what you really use for your question 2 will determine the machine. If just a forums w/ not too many people, even my old machine P3 that I picked up from garbage is good more than enough to handle that, but if you talk about thousands people access per second, you need a real server to handle that
For question 4, try it yourself, since different people have different ideas about it
Have fun,
FREE One A DayFREE PhotoFREE GamesFREE WebsitesFREE Portable GPSFREE WAMP Guides