Hi Braza,
The coin cell option is nice for a lot of low power applications, however a coin cell can only put out around 5 - 10mA, so anything higher power will need a beefier battery. The TinyDuino processor board does have two pins on it to allow connection to an external power source, like a bigger battery pack, which is sounds like you'll need.
Some of your other issues will be due to the voltage difference, so you should choose the resistor values based on the voltage of the battery pack if that's what you'll be using long term.
Thanks!
Ken Burns
TinyCircuits