4. "Doom depends too much on metal and equipment to stand a chance." In response to In response to 0
But if Doom had "prep time" to build a plastic suit and some specialized means of neutralizing Magneto's powers, then sure.
Doom is a genius of incedible magnitude (much more so than Batman); I wouldn't count him out against anyone if he has enough time. Not to say that Magneto couldn't make good use of prep time too.