somethingfishy:
My plan was to talk from Android via Bluetooth to TWO separate Arduinos.
This can be done but I'm not sure that it is something you would want to write home to your mother about. An NRF24 network is made with this in mind and has about the same unit price and performance. You can even use a high power version in the base and get considerably greater range. If you use bluetooth, the base station must be a master and configurable from within the programme.
Do you happen to know if any of the HC-05 boards are plug in "shields" that already have the resistor divider built-in?
No, but I imagine they do. Note that the Itead shield is not an HC-05, it is an HC-06 and therefore slave only.