so... my root should be at system level...... but adaway only works if i flag systemless, and also if i MANUALLY find the host file and try to delete or replace with another patched one..... I CAN NOT DO THIS...... like if the host file is unmodifiable, even if in the attributes i read that the owner is R and W permission
To understand what's happening with Adaway, it will help to understand what's happening with root. It kinda sounds like you've missed the last two years of progress because you have been on an older OS release.
First, determine whether you're rooted system, or systemless (plus if you are sbin).
Using a terminal app, enter "which su" (without the quotes). If the result returns:
"/system/xbin/" that would be a system install. Which means the root binary is on the system partition.
-or-
"/su/bin/su" or something similar, that is a systemless install. Which means the boot image (kernel) had been modified, and a symbolic link is mounted during the boot process for the host file pointing to a non-system partition location. This is done to maintain the integrity of the system partition on "modern" android releases.
-or-
"/sbin/su", you guessed it! That would be sbin mode.
Another way to determine system/systemless if you are using SuperSu - in the app settings, look for an option to install SuperSU as system app. If it's greyed out and the text reads that this option is not available, you are using systemless root.
When installed in systemless, the only way to completely remove root includes a proper uninstall based on the app's instructions AND reflashing the original unmodified boot.img (kernel). Most installs of root back-up the original, untouched boot.img before modifying it and a proper un-root will restore that back-up.
If you don't care about systemless root, you're fine with the system partition being modified, then look for the thread for supersu system version. It will always install the latest release in system mode.
Adaway must be told if you are using systemless install of SuperSu. Thus the checkbox for systemless. You should be using the developer release (Feb 2017?) of Adaway. If you have been making multiple attempts to get Adaway to work, for example, with out systemless checked, setting different paths for the host file, ect. Then it would be simpler to start over.
"Good judgment comes from experience, and a lot of that comes from bad judgment." - Will Rogers