If you aren't going to close your birds in at night, I would suggest burying hardware cloth around your run, or even just fencing the bottom with it. You will also want to construct a sturdy roof if it doesn't have one. If it were me, I would just go ahead and put a door on the doghouse to close them in safely at night. Some years ago when I first got chickens, my hens had a run with a roof and fairly sturdy fence with T-posts, and we never closed the door on the coop. Then an opossum came across the coop, dug in in the same night, and long story short, it did not end well for two pullets and a Guinea hen. 
My bantams do just fine pecking at whole apples. No cutting needed.
They are okay with BOSS, but none of my hens (LF or bantam) have ever liked whole corn unless it's the tender kind like what we would buy to eat.

My bantams do just fine pecking at whole apples. No cutting needed.
