Correct tenses for different sentence situations?

1. What would you say is the correct tense for this (sort of) a basic math problem?

John had three apples, but was hungry and ate one. How many is left?

Could it be this?

How many does he have now?

2. Let us pretend someone is trying to write a class rules for whatever langugage class (eg, Chinese, English or Spanish) that person is in. Which phrase would you use, "much" or "a lot of"?

In this class, much (a lot of?) talking in Chinese/English/Spanish is encouraged.

3. Let us say that a person is writing about his school. Would the underlined present perfect tenses be correct? I think it is correct.

eg,

... My school is great. For one, we have very qualified teachers. We are happy to let you know that we have made some major physical improvements to our existing facilities, like adding several large high-tech classrooms. Also, with a consensus of our students, we have changed our school motto to better reflect our learning goals.