If Bitcoin would become the n1 currency in the world, would this simply be too much to process? I read the wiki which gives me the feeling that it's not so bad, but what I get from the community, and from my understanding of what Bitcoin is, it seems scalability is a major weakness.

My other question is this. It seems we are going to see a network develop with a massive amount of computing power. We have both Moore's law and miner competition working at the same time. This way it becomes harder to attack the network. But it seems like a waste of computing power, computers are performing (senseless) puzzles that just become harder and harder. Wouldn't it make more sense if some of that growing computer power where to go to make the network scale (make it faster and allowing it to handle more traffic)?