I can't roll my r's. How will this impact my chances of survival?

In Russia: no problem. It's considered a mild speech impediment, which is, however, not altogether uncommon. Lenin famously had it, and there's a word for it in Russian, "kartavost". It's recognised that [r] is a difficult sound and most children take a few more years after learning to speak to start pronouncing it correctly. (I couldn't till I was about six.) Also if you're American, you might roll your Rs and not know it; the American pronunciation of "tt" as in "better" or "letting", as a very light [d], is a good enough approximation of the Russian [r]. There's no need to go out of your way to actually rrroll it. (Unlike the double-R in Spanish.)