Second, what if someone mined Wallets instead of bitcoins? What I mean by this is that if someone created a client that continuously created send and receive wallets how long would it take before all of the addresses are used up? How would you prevent this?
There are 2^160 possible addresses, so your investment in wallet mining to find a collision would be astronomical. You would not get any benefit from it --besides the big news-- as the only wallet who would be able to spend that address's balance is the one who has the private key.
I do not plan to do it, I'm throwing it out there as a what if. If all of the addresses have been generated is there a function that will reclaim empty wallets? The only people interested in this are like the two senators that want to see it shutdown.
Ah. It's perfectly legal to generate an existing wallet again.
Yes, someone could generate your wallet and take your coins. It's unlikely.
Unlikely: all the air in the room happens to congregate at the other end; you die of asphyxia.