As far as animals, go to a outdoor supply store and get some fox urine. It will keep rabbits away. Pee on the trees surrounding the patch and the deer will stay away. You will still face issues with mites and what not. Guerilla growing is a pain in the ass IMO. Bat guano is great if you want to stay organic. Make sure you dig your holes out and prepare the soil at least a month in advance or you will cook your plants.