I use for everything except very high heat
You hear people say that olive oil is best in dressings, or uncooked in any event.
However, I do not believe this to be true.
I cook with olive oil all the time.
A doctor from Quebec stayed in my house a couple of years ago. He had been travelling in France for two weeks and was craving a fried egg for breakfast (not the sort of thing they offer in French hotels!). I was glad to oblige. He said he preferred to cook it himself, and surprised me no end when he reached for the olive oil instead of the butter.
As a doctor, he claimed that frying in butter is terrible for your health. And that he always does his eggs in olive oil.
I tried it myself one day, found it delicious, and this is the way I do them all the time now.