Power Consumption and efficiency
I had a quick scan through your figures and they seem good.

Note that your 7805 regulator is dropping 7 V and the circuit is using 5 V. That means that 7/12 of your power is being dissipated as heat in the 7805. You can reduce this in a number of ways.


Reduce your battery voltage to 5 AA cells. The 7.5 V will be enough to power your circuit but you won't be able to drain your batteries as far before the voltage regulation starts to deteriorate. Your 9 V solution would be safer.
Use a buck-type voltage regulator. This will be much more efficient than the 7805 linear regulator and will work over a wide input range.
Do both the above.