Electronic – Get 12v power from NiMH battery

I have an Arduino project that

is powered from 12v/15A dc power source
needs to switch to battery power and still get 12v (dc power may start/stop at any time)
recharge the battery when dc power restored (top-off or full recharge)
if battery dies, will still work from 12v main dc power (dead battery would just prevent it from powering off the battery)

I am thinking of using:

an 7.2v 1500mah NiMH battery-pack (weight doesn't matter, so its not worth the risk using LiIon/LiPo). 10 Cells in series.
BQ2002 – NiMH battery controller
MC34063A – boost converter to boost the 7.2v from the battery controller to 12v (I only need 12v500ma out)

Are there better battery controllers or boost converters to use?

How do I do #3 and #4?

At what rate would the battery be recharged? I want to limit this to 1amp

Will I also need a temperature sensor, at least if I only charge it at 1ah?

Do I need a voltage regulator, or is the output from the battery controller going to be stable enough for an Arduino?

I want to use existing ICs for as much as possible. I want to minimize how much I have to build, but I also can't use an Arduino shield.