@Sanjib: That is why electronics design has been known as a costly investment...
I must admit that the ever-increasing complexity is starting to worry me -- how do younger engineers learn all of this stuff? There wa smuch less to learn when I was at university -- the other stuff evolved over the last 35 years (LOL)
@Max: I agree with your list and yes we would need all of those for a fairly complex boards to more & more complex boards. That is why electronics design has been known as a costly investment (software tools as you mentioned + the lab instruments + certification cost) and those tools don't come for free (for commercial use). Hence depending on the complexity of the design involved, we could sacrifice some of those as appropriate...compromising somewhere else - more bench testing, debugging and possible reiterations. :)
In some ways there are packages that are converging to offer an integrated solution for the hobbiest level, and hence they may not realize that each is its own package. For this you can get away without having some of the fancier things listed that are involved with microwave signal frequencies and high power dissapation. Though the further you go, then many more tools will come into play.