bitcoin-qt, which I think is the Satoshi client?
Correct. The client program that some call the Satoshi client, is also called bitcoin-qt. You also may hear some people refer to it as the standard client.
Doesn't really give much info over how aged particular bitcoins are, or even which address has which amount etc...
No it doesn't. As a matter of fact, it doesn't even list all your addresses that have coins associated with them. It just gives you a total amount of BTC, and allows you to create simple transactions to send. If you run it in server mode, you can use command line tools to send specific instructions for various actions, but that certainly isn't very user-friendly.
Is there another wallet program which can use my wallet.dat to give me demo figures,
If you are going to use another wallet program (such as Electrum or Armory), you might just want to send the coins from the old wallet to the new one rather than trying to import the old wallet.dat into the new client. Of course if your current wallet is made up of a whole bunch of tiny "outputs" that are insufficiently aged, you may have to pay a transaction fee to do so. I'm not sure about the features of either of those clients, but I don't think either of them give much information about the individual "outputs".
and how do I send transactions without fees as it won't let me, even though I set it to 0 and I tried that addnode thing from the wiki.
If your wallet is made up of a large number of very small, relatively recent, "outputs" (Perhaps from SatoshiDice?) you won't be able to use the bitcoin-qt user interface on the Satoshi client to send them without a fee. The program has a built in requirement for a fee in that situation no matter what node you are connected to.
I'm not certain, but if you can come by a single large "output", you might be able to include that as an "input" along with several of your smaller "outputs". This might give you a large enough input total to allow a fee-free transaction?
Example:
You have a wallet made up of 3 outputs of 0.00001 BTC each. To send them all in a single transaction, they would need an age of approximately 14,400,000 confirmations to avoid a fee (approximately 273 years).
On the other hand, if you receive a transaction with a single output of 575.99997 BTC, and you then try to send the full 576 BTC in a single transaction, you should be able to do so without fees after just one confirmation.