A few questions
All your citrus trees look a little yellow.
Have you done a soil test?
Do you live near the ocean?
What are you using for fertilizer and how often.
Citrus trees are heavy feeders and like a slightly acidic soil. Mangoes are less fussy about feeding but when they are young, they need to be fed. Citrus and mangoes need well drained soil and while they like a good deep watering, they hate wet feet.
Yellowing can be a sign of nitrogen deficiency. It usually starts at the bottom leaves but will progress and become more global if not corrected.
Overwatering can cause leaching of nutrients and may damage the roots so that nutrient uptake is impaired.
Unfortunately underwatering can cause similar symptoms, leaf yellowing, curling and dropping.
The bananas look like they are getting a lot of wind. They need a fertilizer that is high in potassium. They are not getting enough water. Bananas need an inch of rain a week. We usually build a well around the banana clump and let the hose run until it fills which can take anywhere from 20-45 minutes. P.S. I have red clay that holds on to water. When amended with compost to improve tilth, it holds on to a lot more. That has to be done every other day. Bananas grow best in wet valleys and uplands. They don't do as well in saline and alkaline soils.
http://lee.ifas.ufl.edu/Hort/GardenPubs ... _trees.pdf
In Hawaii only low chill apples can grow and they are tart. Peaches can be grown in elevations over 1000 ft. I do have a Bartlet type pear and it does fruit. It is still mostly a pet since for the first few years it produced one or two fruit. Amazingly it gives about a dozen fruit now, considering I really don't take care of it.
Happy gardening in Hawaii. Gardens are where people grow.