Agreed on it being a terrible article. Way too many 'clever' turns of phrase. Why make a statement when you can juxtapose some pop culture references? Seems much more of an act of self indulgence than the condemning of one...
But as for your list I think you left out the Occam's razor option:
Plus, if an exponentially-reproducing civilization appeared even in a neighboring galaxy a couple million years ago, we'd probably be able to notice something very strange.
If it appeared in this galaxy, we'd probably never have evolved.
But as for your list I think you left out the Occam's razor option:
5) Rare earth hypothesis
http://en.wikipedia.org/wiki/Rare_Earth_hypothesis