Since blueman-2.1, polkit rules are necessary to prevent root authorization popups on every start of blueman-applet. See https://github.com/blueman-project/blueman/wiki/PolicyKit I suggest using the plugdev group instead, same as used by NetworkManager.
commit 7724be2064e7f967ff1678165c514a698d8c526c Author: Michał Górny <mgorny@gentoo.org> Date: Sat Jun 4 20:02:04 2016 net-wireless/blueman: include polkit rules for network setup, #584300 Add a set of polkit rules that allow active users belonging to the plugdev group to perform network setup actions via blueman. This resembles the rules used by NetworkManager. Bug: https://bugs.gentoo.org/show_bug.cgi?id=584300 Thanks for the suggestion!