If I cook all my food, am I more likely to avoid e.Coli infections?

Yes. You need to cook them thoroughly though. A hamburger that is rare in the middle can still have e coli., . It needs to be cooked well done to kill off the organism.
Yes. A person can expect to avoid e. Coli infections from food if he cooks all foods thoroughly (especially ground meats such as burgers). Choosing drinks that have been sterilized by boiling, bottling, or canning; or drinks that have been pasteurized; is the safe way.