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.
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.
Windows 10 box with drive spaces. Or a real server. At least when it takes a shit(and it will), you can still get to the data. Have had way too many client sites lose data to nas boxes to ever recommend one.