What sort of insight are you looking for ?
I'll go ahead and make the first and most obvious one: A general purpose (non-Safety) PLC cannot be an emergency-stop device. While your program doesn't exclude the use of a safety relay and appropriate E-Stop, pull-switch, and master control relays, it's clear enough that you are evaluating "safety" conditions before running the machine.
It's fine to logically prevent devices from attempting to start when the feedback from the safety system indicates its' been tripped and not reset, but you cannot rely on an ordinary PLC for a safety function.
Setting that aside as a major separate discussion, a couple more comments:
1. I prefer not to use examination of an Output as a pre-condition for other logic. If I can, I use the same set of Input conditions or I use an intermediate logical coil (B3:x/y) to indicate a combination of inputs or another system condition.
For example on Rung 3, you use the System On output as a rung condition, where you could just as easily have used the System On input address. While it's logically equivalent, I prefer to use Inputs as rung conditions when I can.
2. I think you have I:1/12 mislabeled: that should be "Stop PB Feed Hooper". Is this a "hopper" or am I unclear on your industry terms ?
3. I think this is meant to be a manually sequenced start program, where you must push the buttons to start the Picking Belt, the Trommel, the Infeed Belt, and then the Feed Hopper in order.
There are stop buttons to stop each device individually, but it looks like the only thing that will stop them all is the "E-Stop".
Generally I like to have a "System Stop" button that is not the same as the E-Stop. Sometimes it stops things in sequence, or ramps them down from full speed, and sometimes it behaves just like the E-Stop except that it doesn't dump power to every device in the system.