Google has their own calendar app too, which I recently started using.

I linked my Google calendar to the old Mobile Me by CalDAV or something so both my Apple Calendar and the Google Calendar apps. have the same data.

However when I create events in the Google Calendar apps., it correctly preserves the settings I set up for my account, such as the number and type of notifications.

But multiple accounts can probably be displayed as the Apple Calendar shows multiple calendars on top of each other.