It depends on the weather. If you have a lot of rain in the winter like last year, you do not need to water for months. If the summer heats up, you may need to water every day. If you have your tree mulched well, then you can always check around the roots to see if there is still moisture, and if it is not dry, don't water. So it all depends.
In regards to your harvest, you probably have problems with squirrels. They usually do a lot of damage because once they drop a fruit, they go and get another one. To alleviate some of that, you could TRY netting bags or organza bags to put your fruit in to see if it would help. You may have to use more than one bag on each fruit. But the height of the tree is a problem. Amazon has the bags, and some come in different sizes.