If fluid goes into lungs while drinking, can this cause person to choke and die, if efforts to cough it out doesn't work or one couldnt cough?

Yes, possible . This is called aspiration. A massive aspiration event could cause drowning and death. More often, small amounts of repeated aspiration lead to a pneumonia. Unless the cause of the aspiration is addressed, it will continue to be a threat to the person's life and well-being.