Wow! I cannot imagine a 10 foot tree in a pot and not in the ground. I assume you will not be moving this around much?

You water when the plant needs it and not by any 'schedule'. In other words, when the soil is dry an inch down or so. When that will be will depend many variables, including your potting medium, temperature, sun/shade, how active the plant is growing, etc. etc. You would probably fertilize during the period of growth, or just prior to. Others know more about fert than I.

There was a thread about how to determine the ripeness of Meyer. You might try doing a search.