Food Safety – Is it Safe to Cook in a Teflon Pot with a Blistered and Peeled Bottom?

There is no risk to the Teflon itself, or from it; PTFE breaks down at about 500 F, which rice cookers will not achieve, especially on warming setting. Other than that, PTFE is one of the most inert substances known to man, as the atoms are already bound in energetically very favorable bonds: little is as able to displace them without significant input energy (thus the high breakdown temperature).

On the other hand, you should not hold rice for a long time without either refrigerating it, or having it above 140 F (60 C) as there is some risk of Bacillus cereus growing and causing food borne illness.

America's Test Kitchen says that good quality nonstick pans last them about six months.

They're presumably cooking with them several times a day, so if you use it once every couple days, and are as good as they are about not doing things that'll damage the coating, you might get a few years. So your experience sounds roughly normal.

As another data point, they also quote the Cookware Manufacturers Association: "'If you get a year to a year and a half of life out of [a new nonstick pan], we think you got a pretty good deal.'" That's coming from people interested in selling pans, possibly not talking about the best quality, and with experience based on typical less-careful usage, so I'm not surprised they gave a lower number.