For GRE tunnel there are several choices for interface to use as source and destination. Sometimes it seems to make the most sense to use an interface like Loopback as the source/destination (especially when there is the possibility that there might be more than on path that can get to the device. Sometimes it seems to make the most sense to use the actual outgoing interface. And I have seen a few instances where the interface used for GRE was not the loopback and not the outgoing interface. The only thing that really matters is that the IP address be reachable from the remote device.
The answer about where to put the crypto map has changed a bit with IOS version changes. In older versions of the code you need to configure the crypto map both on the tunnel interface and on the outgoing interface. In recent versions of the code it is needed only on the outgoing interface. If you are not sure where your code is in this, my suggestion would be to configure the crypto map on both the tunnel and the outgoing interface and get the GRE and IPSec working (the newer code will work with the map in both places, it is better with the map on the outgoing interface). After you have the tunnels working remove the crypto map from the tunnel. If the tunnels stop working then you need it on both. If the tunnels keep working then you only need it on the outgoing interface.
HTH
Rick
HTH
Rick
