That is definitely a possibility worth keeping in mind but I don't see it happening for quite awhile. This article assumes that the two major parties would somehow lose their institutional credibility, it could happen down the line as third parties end up becoming more established. But the Democratic and Republican parties will not lose their fundraising capabilities or ubiquity enough for third parties to come in and take advantage of a further divided electorate. The two major parties will also have a better and more impressive pool of candidates compared to third parties and that may never change. If it does come down to a third party eking out a plurality though, maybe a national runoff election should be considered under those circumstances.
I don't know, I'm still with the NPVIC. It's an attempt at change and if it needs to be changed too down the line, so be it.
Yeah. A nationwide popular vote system wouldn't change the reality that third parties would still have huge disadvantages in pretty much anything from fundraising ability to candidate quality. They're also the two parties that the vast majority of people have consistently voted for, and that can't be ignored.