Hi,

I'm flying SEA-YVR-FRA-ICN soon, and the flights are operated by:
SEA-YVR: AC
YVR-FRA: LH
FRA-ICN: OZ

I arrive in FRA at 10:50 am and depart out of FRA at 7 pm on OZ the same day.
Since I have more than 8 hours to kill in Frankfurt, I plan on visiting the city during the day (do some sight seeing), and I have some questions about my connection in FRA:

1) Do I need to obtain my FRA-ICN boarding pass in FRA, or should I be able to obtain the boarding pass for this flight in SEA or YVR?
The reason I ask this is because I may try to get back to the airport after I spend a few hours in the city before the OZ check-in counter opens at FRA.
If I don't have the FRA-ICN boarding pass with me, I would have to wait till the OZ check-in counters open, right?

2) Do I need to claim and re-check luggage at FRA?
If yes, is there any place to store luggage temporarily at the airport?
I'd hate to carry a big suitcase with me in the city during my short sight seeing trip.

3) Although I don't think it will happen, if for whatever reason I decide to stay at the airport during my 8-hour connection, do I still need to clear customs at FRA?

Thanks a lot in advance-