The stock antennas are 5dbi, what are you looking for? The way you're asking makes me think you're not really sure what you want, or even know if you do.
Not when they part it out. They just can't reuse the motherboard. Also, I've had friends take their iPads to the police and show them where their stolen phone is at. Police just told them to have the carrier lock the imei and buy a new phone.
I'm guessing you mean a 10.x.x.x ip address, and not 100. You'll need to use a web based phone home app like teamviewer, or gotomypc. You can't nat, or set up server services if you don't have access to their router.
Network activity. Little bit of black paint will fix it. You can't turn off the lights. I'm also pretty sure an open os won't allow that either. It's usually not software that lights up the lights.