You definitely don't need to get too specific with the technical side of things. As everyone else has said they really are looking for your excitement and your empathy skills. They will look at your general troubleshooting skills - looking for the easy fixes first, is the problem happening all the time, is the problem happening on other devices, etc. If they mention a birthday, anniversary, wedding, etc. make sure to acknowledge whatever it is in some way. You will also need to think of examples from your work history that will fit the questions they ask. For example, tell me about a time when you received feedback from your boss at XYZ Company and what happened after that. You're on the right track with reviewing this forum and glassdoor.com.
Glassdoor was a huge help for me. I took all the questions/answer examples I could find from glassdoor and here to make a study sheet. It worked because I'm now just waiting on my BGC. My interviewer also commented that he didn't know if I was coached or what because all of my answers were very Apple like. I was caught off guard a little when he said that since I have a referral from a current Apple employee and didn't know what to say. In truth they didn't give me any specific info on the questions other than saying to make sure to put the customer first (using empathy). I really just studied the same things you're studying so keep doing what you're doing and you'll be fine.