Unfortunately, you can have "Silent GERD", and have serious corrosive damage to your esophagus with absolutely no knowledge that you're having it. If you have inflammation of your esophagus without treatment you can put yourself at risk for getting Barrett's, which is a pre-cancerous condition that is serious, but treatable--with PPI's.
While we'd all perfer to be prescription-free, PPI's are sometimes a necessary evil. I can imagine that it must be hard to believe that you need them when you don't have symptoms. Those of us with severe burning take them much more readily, because they are able to stop a very painful condition.
However, keep in mind that just because you can't feel the acid in your esophagus, it's there just the same. Getting the inflammation cleared up is very important to your long-term health.
While you still should pursue the lifestyle changes, the PPI's that you've been prescribed will help to heal the damage that's already been done. I'm sure you've been given literature by the GI doc, or have been online looking for how to avoid GERD episodes, so by all means follow the advice that you read.
Discuss your concerns with your doctor. I'm sure that he'd be willing to follow you through your lifestyle changes and re-scope you to be sure that they're being effective. The problem with silent GERD is that you can be experiencing serious damage to your esophagus without knowing it. Therefore, you could go merrily away, changing your lifestyle and diet, and end up with continued damage that you're not aware of.
I'm sure your GI doc will understand your hesitancy about taking medications. Hopefully you have a good relationship and can discuss the issue thoroughly with him.
Good luck with your dilemma! There are many here who've experienced the same worries.