Can someone help me diagnose a condition with my Red Emperor Japanese Maple?

Question:I have planted a Red Emperor Japanese Maple in early April, and it has developed some white spots on the leaves. We have had a very strong wind storm a few days ago, and since then the leaves have dried up (similar to the fall) and have begun to fall off the tree. This is only happening to the leaves on the periphery of the plant. Inner leaves are yellow spotted. I have consulted an arborist at the nursery that I bought the tree, and he said it is likely due to over watering. I have been watering on a daily basis (5 minutes) and the tree does experience the effect of an inground sprinkler system. My questions are as follows:
1. Does anyone know of a website that has references with picture of various conditions such as wind-burn, over/underwatering.
2. Should I prune away the leaves that are"crumpling up?"
3. Is it true that the signs of over/under watering are the same (leaves drying up and falling off)?
I appreciate your insight in advance. I really want to save this tree!

Answers:
Signs of overwatering - Leaves turn yellow, dry up and fall off the plant.

Signs of underwatering - Leaves turn yellow, dry up and fall off the plant.

Do not prune crumpling leaves. They will fall off on their own accord.

Japanese maples like moist, well drained soils. Water is as important as oxygen to the roots of all plants. Water in the soil displaces oxygen. If the soil is constantly wet, then there is insufficient oxygen in the soil for your roots to function and you risk root rot. Rot the roots and no moisture gets your leaves, the leaves turn yellow, dry and fall off. Underwater and the same thing happens to the leaves. You need to water deeply and infrequently. Monitor the soil moisture levels, not the leaves. Use your finger to probe the soil around the tree's root ball. If the top 2-3" is dry - water. If it's moist - do not water. Deep infrequent watering promotes root development. Deep infrequent watering trains a tree's roots to seek water. Deep infrequent watering promotes a more drought tolerant tree. Let the soil dry a bit between watering so that oxygen has a chance to penetrate the soil.

Japanese maples do not like hot, dry winds. They fry in hot, direct sunlight. Proper siting provides dappled shade and protection from drying summer & winter winds.

I have witnessed more than one Japanese maple shed its leaves when transplanted on hot, windy days. Early in the season they have time to set new buds and leaf out again. Late in the growing season and they will go dormant early and leaf out the following season.