Autostart iceweasel only when the network is up and Tor is running.

config/chroot_local-includes/etc/NetworkManager/dispatcher.d/60-iceweasel.sh

+#! /bin/sh
+
+# Run only when the interface is not "lo":
+if [ $1 = "lo" ]; then
+   exit 0
+fi
+
+# Run whenever an interface gets "up", not otherwise:
+if [ $2 != "up" ]; then
+   exit 0
+fi
+
+# There's nothing to do if Iceweasel is already running
+if pidof firefox-bin 1>/dev/null 2>&1; then
+   exit 0
+fi
+
+# Get LIVE_USERNAME
+. /etc/live/config.d/username
+export DISPLAY=':0.0'
+export XAUTHORITY="`echo /var/run/gdm3/auth-for-${LIVE_USERNAME}-*/database`"
+exec /bin/su -c iceweasel &

config/chroot_local-includes/etc/xdg/autostart/iceweasel.desktop

-/usr/share/applications/iceweasel.desktop
\ No newline at end of file