It would be useful for people to look at the Camping Stove thread here started by Selco. I agree with the poster Anon who said liquid fuel stoves are “safe” indoors. They were used pre electricity for years. That said.. I would always have a fire extinguisher close at hand and be careful. Same with butane cookers. Even a candle is dangerous and most people today are not expert with the “old” technology.. me included…it’s a learning process. Nothing is foolproof.
The question to ask is how would you cook if the power went off.. and didn’t come on for weeks, months, years… or ever… There would be a series of steps, butane cookers, liquid fuel cookers, and eventually wood burners. What you have prepared in terms of tools (stoves) and fuel, will determine your level of comfort.
The Coleman camp cookers, common in the USA, (I have picked them up cheep in NZ, used, on our ebay) can burn coleman fuel (naptha, white spirit) or unleaded gas, paint thinner, and even kerosene and maybe the new low sulphur diesel (with extra pre heating). There is a propane conversion kit which allows the convenience of gas bottles. The alternative fuels may be inconvenient and smelly.. but you are cooking. Selco would laugh at your concerns about danger and inconvenience .. if the SHTF .. you do what you have to do.
https://www.youtube.com/watch?v=0c6Dht5oMu0e. This video shows the use of the Coleman cooker and a propane conversion, and compares with a normal propane stove. In the comments below the video there is a lot of comment and “experience” which I found very informative. Many people said they picked up old Coleman cookers for less than $20. at garage sales etc. I have linked more at the camp stove thread.