Edit /etc/PackageKit/PackageKit.conf and change the WritePreparedUpdates key to false.
Also remove gnome-packagekit to stop automatic software updates.
$ gsettings set org.gnome.shell always-show-log-out true
Now set in dconf; org->gnome->desktop->wm->preferences
$ gsettings set org.gnome.desktop.wm.preferences raise-on-click false
To disable this you need both of
$ gsettings set org.gnome.mutter focus-change-on-pointer-rest false
$ gsettings set org.gnome.shell.overrides focus-change-on-pointer-rest false
dmesg will now happily display kernel printk timings whether you have them enabled or not.
alias dmesg='dmesg -t'
will happily resolve the issue.