Are lumia 928's through Verizion unlocked out the box ? And if so does that apply to all Verizion phones
Yes they are unlocked out of the box.
I believe all of VZW's GSM-compatible world phones are unlocked.
Are you guys able to send and receive MMS using a 928 on another network? I used a 928 for a while on ATT and while it was unlocked in the sense that phone calls, data, and SMS worked I was never able to get MMS messages to send or be received properly.