Schematic to breadboard layout

Electrically these will work fine, but now you need to put on your mechanical engineer hat (these projects need many hats ) and consider how you are going to mount and use the jacks. I expect this is going to be used in performances and can expect to have the cords tripped over and in general mechanically pulled on. Solder joints are weak mechanically and don't like (i.e. tend to fail which you don't want) when stressed mechanically. So I'd suggest your best bet is chassis mount jacks where the holding nut that bolts it to the panel is not part of the electrical connection (I think I showed some a while back in this thread) and connect flexible wires from the connection tabs to the Arduino which won't be mechanically stressed. As to the pedals they are pretty simple in that they are just like your push button switches the two wires are electrically (if not mechanically) identical to your switchs. As you point out these pedals are normally closed rather than normally open (as your current switches are). The only difference that makes is that you would need to change the Arduino code to consider a 0 as the switch rest state (with you current NO swirches 1 is the rest or not pushed state).