i've decided to turn back system for the battery warning
So i'm renaming the online presence, keyboard and window launch sounds

cd /usr/share/sounds
mv ui-thumb_keyboard_launch.wav ui-thumb_keyboard_launch.wav-old
mv ui-window_open.wav ui-window_open.wav-old
mv ui-window_close.wav ui-window_close.wav-old
mv presence-online.wav presence-online.wav.old
mv presence-offline.wav presence-offline.wav.old

The usb plugging in sounds is ok, for now.

Also, this makes the auto update repository checker check only every 365 days:

gconftool -s --type int /apps/hildon/update-notifier/check_interval 525600

EDIT: every 12m = 43800