I you had bugs in the soil it was probably staying too wet. The new soil should drain better, but the pot is deep and it is in the house so you still need to be careful about over watering. It is best to water the plant in a sink or outside and let it drain and don't let it sit in a saucer of water. If you have new growth that is a good sign. While ficus can adapt to low light conditions, they really would rather be outside in summer. However, it would have to be acclimated to the light or the leaves will burn and then it would have to reacclimate to indoors. Outside the soil will dry faster. Indoors you have to be much more careful of watering since you could easily go 7-10 days before needing water. Use the chopstick test on the plant to test for when it needs water. If the top is moist the middle is too. The other way would be to water the plant thoroughly and afterward hoist it up and feel its' weight. Water when the plant feels its lightest. Plants need good light, but they also need air. Do you have a fan to provide air. They don't like air conditioning or a heater.
For myself, I don't like the glazed pots because they don't breathe. You also have to make sure you have enough drain holes in your pot and they are large enough. You used a bonsai soil mix. I use cinder because it works for me. I used to use gravel and sift it to grade it, but it is actually hard for me to find the smaller gravel. I have recently found a source for akadama. I don't use some of the commercial bonsai mixes because they still contain some compost in them that will hold on to water. I water my plants daily but they are outside.
Happy gardening in Hawaii. Gardens are where people grow.