Sequence Options for multiple night imaging

Correct, only at a target level.

You cannot have any active Lights after a park. If you plan on doing multi night imaging like this it is probably best to disable the targets/events that you won't get to.

We plan on adding Start/End altitudes and allowing those to fill in the time or vise versa.

Not directly through SGP. You could write a VB script and have SGP call that script.

Thanks,
Jared