Converting SQL Server recovery model simple to full
BOL says about recovery model that


  Recovery models are designed to control transaction log
  maintenance. A recovery model is a database property that controls how
  transactions are logged, whether the transaction log requires (and
  allows) backing up, and what kinds of restore operations are
  available.


Please note that recovery model controls amount of logging in transaction log file and in case of disaster how much data you can recover. It has no relation to amount of inserts or updates or number of column in you table.

You can keep simple recovery model if you do not require point in time recovery. You can take full and differential backup in simple recovery model. If you want to change recovery model to full then make sure you take regular transaction log backups after changing recovery model. Changing recovery model should depends on how much data loss you can afford or agreed between you and client basically the RPO and RTO.