Constantly using the same change address reduces the privacy of your transactions. It makes it easier to analyse your transactions and link them together.
Yeah but then I'd have to eat the Tx fee when I decide to consolidate each one of those change addresses which might hold an amount less than my Tx fee setting. Can I just do a 0-fee consolidation into an address in my own wallet? What are the risks of that? I'm not too concerned about confirmation time since I'd only do this periodically. Sorry for the n00b questions; I'm new to this Armory stuff :]
Reusing the same address will not help. You will still have multiple inputs in your next output, it will require the same fee regardless of whether these multiple inputs have the same address or different addresses.
Doing a 0-fee transaction to yourself will lock up your coins until it confirms. If it never confirms, the transaction eventually goes away. So there is no real risk. You should, however, be aware that if your transaction is too small then a fee may be required before the network will even consider transporting your transaction. I think that Armory in that case refuses to send the transaction without a fee.
