Change Addresses

I'm trying to understand change addresses, because I had the following situation happen. I backed up my wallet and soon after proceeded to have a computer crash. This wiped my system. Pulled in the wallet I had backed up, and was missing many address labels I had created between backing up and failing (far less than 100, addresses were still stored in wallet). Understanding that a wallet had 100 addresses preloaded, I started recreating addresses and matching up transactions I remembered. I got most of them, and things were ok. The other day, after learning about change addresses, I wondered if creating new addresses in my wallet would uncover those change addresses. It appeared that it did. I have created over 50 test addresses new from my wallet and all of them but one have activity on blockchain.info.

Here are my questions.

1) Is there a way to view all the change addresses that have been created for me or do I have to keep creating them until I have them all?
2) When I create a new address for receiving in bitcoin-qt, does it randomly pick addresses from the pregenerated pool or proceed in order? I had one address that I generated that showed no activity, and then the next one did.
3) Is this optional functionality? Is there a way to turn this on and off?
4) These change addresses all have 0 balance. Do they get transferred? How does this all work?