Forget Indo-European, learn to speak World! :-P
Call me cynical, but it seems to me that many sounds, under the right conditions, can be said to be associated with many other sounds. To wit: the letter 'g' is used in places where elsewhere are found 'w' (guard/ward), 'y' (OE gear > ModE year), 'c' (Germanic verbal prefix ge- is ultimately related to Latin prefix co-), or no letter at all (OE gear / Sw år). But this doesn't mean that any of these letters can fill in for any of the others. (E.g., you can't say that sag, say, saw, and sac have a common source just because, in other circumstances, those letters are related.)
So, if you ignore circumstance I suppose you can fabricate an etymology or linguistic connection for almost anything. Given the fact that all humans work with the same laws of physics and anatomy of mouth, throat, etc., it's probably inevitable for genuine coincidences to spring up now and then. Considering all the words of all the languages of the world not on that list, what is there might just as well be coincidence as a legitimate connection. Anyway you'd have to judge case by case, and I'm definitely unqualified for 99% of the languages listed.
Having said all that, I'll admit gaetanus and I had the great (albeit tongue-in-cheek) idea in college to reconstruct "Adamic", based on things like Greek kata and the downward aspect we saw in the word kowtow. We were like a linguistic mafia that could force a connection between any two words you liked: You need to establish a link between these two words? ... We have ways ... We'll make 'em an etymology they can't refuse....