There exist varying answers to your questions. Some researchers believe it is bile, not acid, that damages the esophagus. They feel that PPI's only make us more comfortable by reducing the burning sensation from the acid. These people state that bile is a normal part of the stomach environment, while others seem to believe that bile is not usually in your stomach.
Once the LES is stretched, some say it will never close properly. Strengthening your diaphragm can help, here is the exercise:
Diaphragm exercise is a conscious technique of
breathing using the diaphragm, rather than using
the lungs and the chest, to create each breath. This
means expanding the abdomen to inhale and then
contracting the abdomen without exhaling. Do this
abdomen exercise 5 - 10 times, then exhale.
Repeat this process 10 times. It may help to place
your hands on your abdomen to maintain the focus
on the expansion and contraction of your stomach.
This exercise can be done sitting, standing, or lying
down. However, caution should be taken initially
since excessive and deep breathing can induce
hyperventilation. Hyperventilation may occur, so if
you feel lightheaded at any time, stop the exercise
and attempt it again the next day.
Triggers are quite individual. Many people have triggers that are not on the list from the doctors. Many trigger foods are perfectly safe for most of us to eat. You should keep a food diary to identify your personal triggers.
The quantity of food you eat is far more important than what you eat. If you eat too much, the LES will continue to stretch, and your problem will get worse.
The Fast Tract diet helped me get off meds, I only take a couple of TUMS daily. There is a thread here on Fast Tract which contains more details.