260 degrees is almost unreachable. Water of course boils at 100 degrees, keeping the temperature down. When cooking with fats and oils, you always keep the temperature below the smoke point. Those are generally below 260 degrees, except for some rare oils.
Even then, you rarely heat oil just for the sake of it: there's usually something in the oil, and that will burn. This will produce acrylamide (a cancer-causing chemical) at temperatures well below 260 degrees.
The real risk is an empty pan. Heating that will cause a quick rise in temperature, as there's nothing to keep the inside cool.
For toxicity, I'll assume human toxicity. I don't think the danger to birds is disputed. As is usual with toxicity, the important part is the dose. Here we see a bit of a problem with the EWG site linked in the quqestion: they're using scare tactics. Their standard for doses is "have been detected". Not medical risk. The FDA continues to list Teflon as "safe for cooking"
As for "other chemicals being released", it's hard to measure this. Cooking releases hundreds, if not thousands of different chemicals. Many of them you can smell; you'd call them "flavors" or "aroma's". Non-stick pans are hardly unique in this respect.