These plants, when new, have a tendency to drop a noticeable amount of leaves. Don't panic, this is due to the trees being grown in ideal conditions, they are adjusting to your environment. The leaf loss may occur over several months. Pick up fallen leaves and remove yellow ones still on the plant. Cut off dead and dry twigs. This helps light to penetrate to the inside foliage, to promote growth on the inside.
There are several different varieties of ficus. The plants with similar looking leaves are ficus nitida, nuda, and a longer leafed variety is called alii.