This is how *cryptocoin wallets work. Addresses are just for identyfying account on exchange and not matter address is cleared if funds credited. For example, if you withdraw, you will receive from different addresses than deposited.
Maybe they should be care about spending not fully confirmed transactions but it is separate from trading system.
Don't worry. Your money is probably safe, if not - not because of this.
I made another bitcoin deposit today
Yes - you have correct answers above. As we require 2 confirmations to post BTC to your balance our wallet needs only one and start using your coins for withdrawals. It does not mean we use your C-CEX balance for that. It's different things. So you of course got your deposit according to BTC amount in this transaction to C-CEX balance and you are able to trade it or withdraw when you need.
Provided that the exchange can use our balance and our only source for tracking our transaction is through the blockchain, and hypothetically speaking, our funds just disappear. Then we have no way of tracking and justifying our balance because the blockchain is saying you have zero balance.
So if I didn't trade my btc deposit to an alt, and I decide to move my btc to a different btc address, how in the world would my current ccex btc address display that transfer when the picture blockchain.info showed me was that a transfer already took place?
BTC balance of address on blockchain can't be equal your virtual C-CEX BTC balance. Reason - we do not send coins between addresses when people trade. When you withdraw from C-CEX you get valid transaction ID which contains your exact amount of coins you withdraw.