Well the screen is basically just to keep the dubia roaches inside the tote, and to keep foreign objects from entering. Personally I keep the screen off, since it allows me to check up on them to see food/water levels without having to remove the whole lid, thus possibly disturbing them. I lay the screen on the hole where it should be glued, and i just lift it up when I want to peer inside and replace it when I'm done.
I chop my oranges up so they can eat it faster. It's not necessary, I just do it personally cuz I like to see them eat fast lol. Also will try bananas soon, I finally remembered to buy bananas and will feed it to them, I wonder how fast they'll eat it lol.