I would be inclined to fabricate some sort of guard to go in front of that jigsaw, incase the blade breaks, very unlikely if you are careful, but you dont want it flying at you. A sheet of perspex, fitted at an angle would probably do.
Bear in mind to that if the sandpaper, starts to come loose it will sting like buggery every time it hits you in the hand.
I would try to find a way to have an emergency stop of some sort especially on the jigsaw. Or at least ensure the PowerPoint is close enough that you can reach it to stop it. Groping under the bench while your finger is being munched would not be fun.
Aside from my party pooping, good work on inventiveness.