I would like to have an offline wallet with Bitcoin Armory on my old computer, and use my other old computer as a 24/7 miner. Further, I would like to mine on my current computer when I am not using it for anything else. I want both of my miners to be able to deposit and withdrawal BTCs to the offline wallet. How would I set this up? I feel like it should be as easy as importing the watching-only wallet onto both computers; is this correct?
You can deposit into both wallets just fine. I have not used bitcoin armory, but with bitcoin-qt client there are hidden addresses created when you send BTC from the wallet. Something to be aware of. It's possible to lose BTC. I think you may be ok though with BA. Maybe post this question to the armory thread to be sure?
https://bitcointalk.org/index.php?board=97.0