-`p` to power off selected the selected partition's drive (also called safely remove). It can be done only when all partitions of the drive are unmounted
-`ENTER` to open selected mountpoint in current tab of the ranger
If there is trouble with permissions, then you need to create group `storage` and add your user to it. Then you need to update your Polkit or PolicyKit permissions like it shown [here: https://github.com/coldfix/udiskie/wiki/Permissions](https://github.com/coldfix/udiskie/wiki/Permissions)