What happens if you put the same bitcoin wallet on 2 computers?
Nothing special. You'll just have access to your balance on 2 computers for the next 100ish transactions. However, please don't do this right now. The software currently doesn't detect this, so if you spend Bitcoins on one computer and immediately spend them somewhere else on the other, your wallet will become corrupted, and we'll have to walk you through fixing it.
What happens if i delete my wallet and get a payment? If i restore the wallet from a back up such as a USB will i get all the payments that came after it was original lost.
Yes. Your backed-up wallet will check for new transactions once it is restored. Be sure to make a new backup every 100ish transactions, since you only have 100 extra keys at a time in a wallet.
Yes I wonder this too.
What if I backup my wallet and remove it.
Get some bitcoins to the same computer.
Will a new wallet be created?
Bitcoins are not sent to a computer - they are sent to addresses. They can only be accessed by the wallet that has the private key for the address.
Will my backedup bitcoins be gone if I restore the old wallet (on another computer?).
(Maybe dumb question.)
No, as long as the wallet contained the keys for the addresses the bitcoins were sent to and they weren't already spent.