First, i know about current status of out of the boxes' 1.1.2 phones.

If i put my phone in recovery mode and go to iTunes and click on Restore, and iTunes restore 1.1.2 AND firmware, can i be sure it was revirginized, in the same state it was before any change i've done, and is it safe even to be sent back to Apple?

(No, i will not be sending it)