Hi all! After a day of NetHunter use I would share some tips I learnt the hard way
Tested on Nexus 7 2012.

1. For anyone needing to keep the device under charge while using an external usb device, an Y-cable work well: however, remember to plug the Y-cable FIRST on the charger (already plugged into the wall), and NEXT to the Nexus device, otherwise the device doesn't start charging.
2. If you need to crack for some time, to prevent the device going to sleep mode and cutting usb host, simply check, under the Menu button of Terminal Emulator, "Take Wakelock" and "Take Wifilock". Now you can turn off the screen while keeping the device active.

Anyone that has other advices please reply!