I've had a look at look at Calendars 5 and Fantastical 2 iOS iPhone apps.

But I still need three things that are lacking
1) Ability to handle multiple Google accounts - not one Google account with multiple calendars but multiple Google accounts. Somewhere in there, multiple TripIt calendar feeds need to be brought into the picture.
2) When I create a new calendar entry on iOS device, the ability to sync this new entry UP from iOS app to Google Calendar.
3) Ability to sync down text and info entered in the "Description" text field in Google Calendar (web).
4) [Preferable but not required] Uses Google Maps app on iOS rather than Apple Maps app when requesting a map of location based on calendar entry (address/location field of Google Maps web).

Tx!