Is it possible to view others’ transactions in bitcoin client?

This seems like a really basic question, but I’m having trouble searching for answers on it. My understanding is that my bitcoin client (Bitcoin v0.7.1-beta) has basically theoretically downloaded the entire transaction history of every bitcoin transaction that has ever occurred. I can see my own transactions in the Transactions screen. Is there a way to see transaction with wallets that I haven’t imported or created on this client? I’m just trying to get a full understanding of bitcoin technology here. Is the reason the client doesn’t show transactions from other wallets due to:

  1. User friendliness – it would be overwhelming to have to search through all wallet addresses when most people only care about their own (is there a way to override that?);
  2. Technical limitations – it’s impractical to consider every transaction in the huge database when you want to list or look up some particular piece of information;
  3. Design limitations – Not every transaction is actually there with all the information necessary;
  4. Privacy concerns – By making it too easy to view others’ transactions people would yell out about privacy more vocally;
  5. Something I missed?

Better or worse to mine multiple workers on one machine?

I use cgminer on Ubuntu 12.10 to mine bitcoins in the 50BTC pool. I have three workers set up. If I run multiple instances of cgminer, each targeted at their respective workers (1, 2, and 3), would this increase profits or just waste power?

I notice this because cgminer only uses about 80-90% of my GPU (Radeon HD 6570) anyway.