A. The usual problems are finding a good spot in the landscape for the garden, getting the organic matter up to decent levels, planting at the right time and watering correctly. All of the vegetables you mention as well as grapes have no trouble handling our sun and temperatures.
Shade cloth, around 30 to 40% and no more, can improve the quality of many crops but not all crops. Okra for instance does not tolerate any shade at all. It has beautiful leaves but no edible production. Corn is the same way.
|This is a ten foot wide hoophouse with 30% shade cloth. 30% does not seem like much in the very bright summer sun but it is enough to give some relief to vegetables resulting in better quality.|
Put the garden where you can regularly see it from inside the house. Out of sight, out of mind.
The garden needs 6 hours of sunlight at a minimum. Eight is better. The worst spot for a summer garden is on the west side in full sun. The best location is full sun in the morning through mid-afternoon.