First, I want to thank the people in this thread who are actually making posts with content to help those of us out who are still in the interview process. Your contributions have been invaluable.
I was able to apply information from this thread to my second interview today, and the recruiter seemed to really take a shine to me and told me she'd be moving me on to the actual job interview and that I'd get an email to schedule that soon. Lo and behold, the email arrived within 3 hours and I have an interview scheduled for tomorrow, which I gather is a fairly short turnaround. I hope to do as well tomorrow as I did today.
A little information from my second interview for people looking for that sort of thing:
1. It was very personable and didn't really feel like an interview. We had a conversation and interspersed into it were the normal interview questions like 'tell me about a time...' and 'what would you do...' and a few roleplay scenarios as well.
2. Empathy and making the customer feel like they were a real person that mattered seemed to be paramount. I didn't know some of the specific answers to the questions although I was able to general troubleshoot them, but the recruiter told me that it's not a big deal and that training would cover that kind of thing if I was hired.
3. I smiled a lot, she smiled a lot. There was a lot of smiling. If you're not a normal smiler, think about how happy you'd be if you got hired and smile about that. Smiling really communicated that you're comfortable and having a good rapport with the person you're talking to. It leaves a positive impression and will color their entire recollection of you later. Be happy about something even if it's not what's happening right that second.
4. When I didn't know the answer to one of the questions, I took it as far as my general knowledge would let me, empathizing with the 'customer' the whole way, and then simply said 'I'm not sure what to do next'. She seemed to appreciate that instead of me bumbling on and trying to BS through it.