That's a good point about excluding Alaska in the area calculation; Alaska is almost 18% of the land area of the US, so pulling it is significant.

From the perspective of population, I honestly don't know why I didn't consider that when thinking through this originally. It seems so obvious in hindsight, lol.

GDP is a little bit more complicated. By pure GDP, it looks like Brazil and Canada kind of flip back and forth depending on the year (right now Brazil is just barely above Canada); though if you look at per-capita GDP, Canada is way higher up the list.