You should check out xdotool
Here's what someone else did to accomplish your goals:
In my home directory (for me it is /home/pi) /.config/lxsession/LXDE-pi the autostart file is:
@lxpanel -profile LXDE-pi
@pcmanfm --desktop --profile LXDE-pi
@xscreensaver -no-splash
@xset s off
@xset -dpms
@xset s noblank
@sed -I 's/"exited_cleanly": false/"exited_cleanly" true /~.config/chromium/Default/Preferences
@chromium-browser -noerrdialogs --disable-session-crashed-bubble --disable-infobars --kiosk http://<path to online html document #1> OR file:////<path to file on the pi>
@lxterminal --command "home/pi/scripts/sleep.sh" ***This is where I launch xdotool after a short delay. Xdotool always worked in a terminal window for me.
My scripts reside in ~/scripts. sleep.sh uses xdotool to do a Control+Tab every 10 seconds. This moves the kiosk from one tab to the next.
sleep.sh
#!bin/bash
xdotool search --onlyvisible --class Chromium windowfocus
watch -n 10 xdotool key ctrl+Tab # This sends <crtl+Tab> every 10 seconds