Same...never knew I had it until I fasted once and got jaundice. Apparently it is a benign condition.
I'd never heard it is related to GERD, so please inform me if you have found info on this.
I researched it once and found that people linked a plethora of symptoms to it, although Dr's will tell you that it has no symptoms except jaundice. One symptom some people get is apparently RUQ pain as well, although, again, to my knowledge no GI would agree with that. But a page out there dedicated to people with Gilberts that I found when I researched it a few years ago had people compiling symptoms that they felt were related to it, including some of the things you are mentioning.
Tell me more about the link to GERD though...I've never heard that before.