The getURL and postURL tasks automatically enocodes the passed parameters. So you need not explicitly encode the posted values.
But postURL task do not support directly writing data to a body of post request. So you can not use postURL task for Google API. We will analyze the possibility for making post request to google API. We will keep you updated.
We use www.batchgeo.com. You can export the group and copy and paste...every simple. I also agree Zoho would be smart to add a button that allows us to do this inside Zoho CRM. Many sales managers need to map territory with a group of leads/contacts/accounts etc....not just one. Hopefull this is in the next update. In the meantime we will continue to export and batchgeo.