Wow, this is some incredible stuff!!
Couple things I noticed...
Those pictures from the cell phone I believe are Giovanni. He looks strapped to the ground by his waist and wrists.
Just something that might be important, there's only 4 pieces of gum left in the pack of 12 that contained the audio tape. 12 and/or 4 may be important here?
In the phone call with Ace, it seemed extremely odd that he was so concerned about the color of the cell phone. This makes me think something about the cell phone needs to change, or it's some sort of code he has. (Black being the signal to end conversation and White being the signal to continue)
I have a feeling there's something hidden in the cell phone as well, whether it's literally inside of it, or just in a file stored on the phone.
Ace and Uboat refer to themselves as XO and XX, and you found 7 X's on the pencil. They may not be related, but perhaps the 7 X's are refering to someone or a group of people as well? (On a side note, what were the X's on the pencil made with? Is that item in the case too?)
BTW, yes, I did register just to post this.
I've been following you guys since Transmission 2