The red wart-like structures on the upper surface of your maple leaves are maple bladder galls. Maple bladder galls result from abnormal leaf growth due to feeding of a small mite, Vasates quadripedes. In early spring they are green but they turn red and eventually black. Leaves may become so covered with the galls that they completely twist out of shape and may drop early. Galls often cause a lot of concern with homeowner but they do not seriously affect the health and vigor of a healthy tree. Controls are usually not necessary. http://ohioline.osu.edu/hyg-fact/2000/2004.html
 We need more information before we can answer your second question.  Are the pepper and bean leaves completely gone? Are there holes in the leaves?   Are the leaves discolored.  Could you send us a picture of the damage?

here are pictures of my beans and peppers.. thanks  :-)

    Insects that attack vegetable plants are divided into three groups - sucking, chewing and boring.  Insects that have chewing mouthparts that leave irregular shaped holes attacked your peppers and beans. Unfortunately there are many insects with chewing mouthparts so it is difficult to know which ones are doing the damage to your plants.  Grasshoppers and Japanese Beetles are examples of two insects with chewing mouthparts that eats a wide variety of plants including vegetables. The following is a list of the most frequent pest of beans and peppers with chewing mouthparts. The bean leaf beetle, Cerotoma trifurcata, is a pest of green beans, soybeans, clover, dry edible beans, and several leguminous weeds. Bean leaf beetle adults are about ¼ inch long, oval-shaped insects with a black triangle at the top of its wing covers.  Their heads are visible from above. Most bean leaf beetles in Minnesota are yellowish-green with four black spots and black markings along the outside margins of the wings. http://www1.extension.umn.edu/garden/insects/find/bean-leaf-beetles/ The cabbage looper (Trichoplusia ni) feed on leaves of a wide variety of plants, including beans, beets, cabbage, carnation, cotton, kale, lettuce, nasturtium, parsley, peas, potato, soybeans, spinach, tomato. Injured leaves appear tattered, with irregularly shaped holes removed between major leaf veins. This caterpillar is green with a thin white line along each side of the body and two others near the middle of the back.  Insects that feed on Peppers are Colorado Potato Beetle (Leptinotarsa decemlineata) ,  Tomato hornworms, Manduca quinquemaculata, are very large caterpillars that eat tomatoes and peppers http://www.extension.umn.edu/gardeninfo/insectgallery/garden/caterpillars/large/tomatohornworm.html , and European Corn Borer (Ostrinia nubilalis)