Importance of rolling 'r's in Finnish?

Well, it is indeed important to learn the R because it can sometimes differentiate words from each other. An example: V�ri (colour) vs. v�li (space). Please note that the Finnish R is NOT the one that is in standard British English, it is more similar to what David Coulthard has (the former F1 driver). Though, you will do fine as long as your R is not too similar to L.