Automation and Integration of several different Google Spreadsheets

We have several spreadsheet databases and client lists that are fed by google forms on our website and some that are maintained manually. We are looking to cut down on double and triple entry by automating some of the tasks that are currently done manually. We also would like to explore connectivity between our Master Client List and the google calendars we use and integration with Mail Chimp. For example, the client status field in our google doc spreadsheet would be changed if a customer was removed from the calendar, and their status would also be changed in our mail chimp email list. Also if a status was changed from pending to active, an email or form submission would be made automatically to our billing department.