If you are going to hit karelia do not bother attacking the UK fleet, unless for some reason Karelia is left with two infantry or something similar. I have seen beginning russian players play defensively (and foolishly) like that before, so it does happen.
I tend to agree with guderian that taking territory in africa is important, while hitting the UK. Russia is usually not an option. However, I typically need the infantry I have in europe just to stay afloat, so in a no-bid game I usually will not transport to africa. Of course, in a no bid game it doesn’t matter too much what I do. Africa, and germany, will probably fall.