I cannot help much with the adjustment questions as I have little experience with performing these type of adjustments on the RS machines. RS support would be who I would direct this type of query to.
I can confirm that your webbing in the photo is incorrect. It should feed from the core in the front, around the lower silver idler roller bar (located below the lower main roller), and then up and around the lower main roller, through the nip, and not around the front of the removable front tray. You would remove the front tray to web the print, then replace the tray after it has been properly webbed up.
could you take a picture on how you do it please