There's a significant difference between intentional colonization in the era of large ocean-crossing ships and languages spreading in an era of smaller craft without a central goal of expansion.

I don't know. I kinda assume most language families are somewhat land contiguous and I take indo-european as the exception that confirms the rule. That's why austronesian is so interesting.

I consider the languages of Western European colonial powers to have achieved a sort of heightened mobility when they more or less mastered extensive sea travel.

Something that I've always found interesting is how the two large Polynesian areas of Hawaii and New Zealand and currently dominated by the English language, but this domination came to New Zealand from the British Empire as it traveled east, while it arrived in Hawaii from the United States traveling west.

The English language capturing the world is unlike anything else.