Can Verizon tell if I hacked my phone ? Like if I put a rom or anything on it after I sbf?
SBF completely reflashes the phone to stock.
But make sure you perform wipe data/factory reset as well; SBF often doesn't touch stuff in /data (at least for me).
Sony LT25i “Tsubasa”, stock, rooted, locked bootloader [Android 4.1.2 “Jelly Bean”].
Maximum speed witnessed over LTE: 98.2 Mbps down / 48.5 Mbps up; Average speed over LTE: 72.9 Mbps down / 45.7 Mbps up.