There should be a way to store a default reminder time of lets say "15 mins" before the appointment when creating a new entry. It is kind of tedious to always have to do this manually for every new appointment and sometimes you forget ...
I'm not sure I understand. There is a setting in options | Alarms | Default alarm setting for events that can be switched On. Do you mean something else?
No, I meant this. With the difference that this option should be available not only globally but also for each Calendar.
I think, this should be handled in the more general "per calendar" settings bug.