I do lots of things perhaps I "shouldn't"
I don't warm up my car, as in the engine, even when its frigid out. I will turn it on, but to defrost and scrape the windows. So it does warm up that way. But if its cold, and i don't need to do that, i get in, start it up, and drive off. I've never ever had ANY issue becasue I don't.
I routinely eat food that is past the "sell by" date. If it smells and tastes ok, or has no visible mold, or its something like crackers that won't actually "go" bad, I don't care.
I too defrost stuff on my counter, when I'm home to remember to put it back in the fridge. And I frequently leave my leftovers out for an hour or more. I have yet to poison myself
I wash things that say dry clean only, if it seems that they woudl be ok. Either by hand, or sometimes in the washer, in a mesh bag. The only thing I have ruined is a blouse, red with white dots, that SAID machine wash cold, which I did, and it ran. Yet my co-workers who bought the same top (from our store) had no issues whatsoever. I just don't care for the smell (and I can smell it) of the dry cleaning chemicals on my clothes. Plus I'm cheap.
I do my laundry as follows: Darks, whites and lights (i don't bleach and frequently don't have enough whites to make a full load), sheets and towels, and undies and socks. Darks are washed in cold, whites and lights in warm, and sheets and towels and socks and undies in hot. But I've also been known to throw a stray dark in with the lights and vice versa, rather than wait for my next laundry day.