Deleting Iphone from iCloud My phone is backed up daily, so all my pictures...are in my iCloud account. My phones screen completely shattered and part of the body is warped and I am waiting for my replacement phone to get here. 

My first question is, how do I erase my device as I cannot use the screen at all and Itunes wont let me access it without the "phones" approval or can I just delete it from iCloud settings?

Second question, if I erase my phone/delete the device from iCloud will all my stuff be erased in my iCloud account as well?
You can erase your iPhone from the iCloud website or from any other device that you've setup with Find My iPhone.  Here are instructions for doing the erase.

When you erase your iPhone, your data in iCloud is safe and won't be erased.  When you get your new iPhone, you can restore the backup to the new device, if you want.