In my case, adaway is working now, and I do have the /su/su.d/ script and the /su/etc/ hosts file. But even in this scenario, everytime I try to update the hosts file, it asks me to create the bind again, and after pressing ok the host file is updated.. but the symlink isn't created somehow. Kinda strange.
EDIT: That was before. After a reboot, adaway shows no host file exist (even if on the /su/ partition it does exist), and there is an error creating the symlink now. This seems like a head/tails coin everytime I reboot o.O. The script and hosts files are still in place, but apparently adaway doesnt detect them. This is being a headache, why it worked flawlessly on systemless SuperSU on M and not on N :S
EDIT2: After deleting data again, activating systemless, rebooting, and trying to apply hosts (this entire seq. for the second time..) now it seems to work flawlessly with any message about symlinks or anything o.O. I think the issue may have been some M stuff still conflicting, but I wonder how that survived the first data wipe.