I've unlocked the boot loader with the ASUS utility available on the ASUS web page, and have rooted it successfully with vROOT (the framaroot approach described in another thread did not work for me).
So, is there another way to get the network unlocked? Either by getting a code for the IMEI, or via USB?
Just found that my new ME302KL (LTE) just bought via E-Bay has an AT&T network lock - it requests a network unlock code when I insert a SIM. As I don't have an AT&T account or SIM, I cannot get it unlocked from there. Found a web site that wants 50$ for providing an unlock code, which would then take two weeks for processing.