Hello
You can uninstall Whatsapp but only the downloader will remain since it is part of the system, you will need to root your AG Chrome vibe to be able to remove system apps. see how to root your phone here http://www.satechhelp.co.za/1653/Root-Ag-Chrome-Selfie?show=1653#q1653
To fix Whatsapp bugs: Most specially if it says date and time are incorrect, even they are correct.
- Go to google play store.
- Touch the "Manu" icon (top left) for more options.
- Touch My apps & games.
- Scroll to whatsapp and touch "UPDATE"