Congrats on the interview. I'll try to help... All this info pertains to the Philly region, they may handle things differently in other regions.
1. The interview is a reactionary one. They will ask you questions such as: Tell me about a time you dealt with an escalated customer, what was the situation, how did you resolve the issue, and what was the outcome? Say for example your working in a kiosk, the competitors are all around you and offering free phones with activation. How would you overcome that to close the sale?
2. I work in a high volume store in the 'burbs of Philly with 5 other sales rep's. Two of us are making over 70k/year with the average rep makeing about 50k. Also it isn't uncommon for rep's working in a kiosk to make 50-60k/year. If they place you in a kiosk then on Saturday and Sunday just hang out at the pizza place across the way and see how much business they have. If they have 2 or 3 reps and no customers to sell phones to then it probably isn't a good thing. You still may want to take the position though with hopes of transferring to a high volume store when a position opens up.
3. Hourly plus commission.
4. Yes, and they will also do a very extensive background check. Do not lie or fudge anything on your application, including employment dates, and salary. If you lie they will find out and you most likely will not get the position.
5. I don't think they pay moving expenses for sales rep's.
6. Yes, they do pay for you to go back to school. Not sure of the details though.
7. Benefits start day 1 of your hire date. They have regular PPO and HMO through Cigna (I took the PPO and for whatever reason it's cheaper then the HMO, not sure why), dental through Aetna, vision through another company (can't remember who), life insurance that is 2x your annual pay (not sure how they figure it out of you've worked for them less then a year and you die). I'm single with no kids and I pay $36/month for the benefits. They also offer an employee phone program, but you have to be employeed 2 months to get an employee account.
Good luck with the interview.