Living in the electric city, my area has lost power for a significant (over 10 minutes) amount of time twice in the last 10 years. So my statement about being able to use it without power isn't quite from experience.
My stove burns natural gas, and I have never in my life turned on the exhaust fan unless I needed to get some smoke out of the room, (I always test the smoke detector while cooking, with my cooking) and I haven't keeled over from CO2 poisoning.
If natural gas is a viable option, use it. We have municipal gas that comes from the street, so tanks aren't an issue for us. If you have a similar option, I wouldn't hesitate with gas.
As for the danger of induction cooking, there is more energy and harm from the EM radiation that comes from the sun or some powerful halogen lamps than an induction stovetop. If the alternative is an open fire that DOES consume oxygen, then neither are worse than each other going by anecdotal statistics alone.
As a person who likes to cook for myself, gas is the best way to work. You can control the heat WAY faster than you can induction. You don't really loose any amenities either, as my gas stove has piezoelectric spark plugs (get a pilot light stove if possible, though, as the sparkly on one of our burners works only about half the time, whereas a pilot light will always work unless it goes out, which is rare in my experience), electric oven, warming drawer, and broiler control, as well as a convection fan and timer.
Electric, in my opinion, is more suited to smaller installations, or installations where gas isn't practical. I see them as substitutes, and not alternatives. IMO tho.