2.2  Assume the Moon's orbit is circular.  Suppose you are standing on the side of the Moon that faces Earth.  How would Earth appear to move in the sky as the Moon made one revolutin around Earth?  How would the "phases of Earth" appear to you, as compared to the phases of the Moon as seen from Earth?

Since the same side of the Moon faces the Earth all the time, the Earth would remain stationary in the sky - no rising or setting.  The Sun, however, would move in the sky, so Earth would show phases.  These phases would be opposite to the Moon's phases as seen from Earth.  At the time of a new moon, the Earth would be full.  At the time of a full moon, Earth would be new.

2.8  Does the occurance of solar and lunar eclipses disprove the notion that the Sun and the Moon both orbit around Earth?  Explain your reasoning.

No.  Eclipses are caused by the relative positions of the Sun, Moon and Earth.  They can be on a line if the Sun and Moon orbit the Earth or if the Earth and Moon orbit the Sun.   (Too bad - would have saved a lot of confusion!)

2.11  The tilt of Jupiter's rotational axis is 3 degrees.  If Earth's axis had this tilt, explain how it would affect our seasons.

We wouldn't have much in the way of seasons if Earth's axis of rotation were tilted only 3 degrees.  The weather would get colder the farther you moved from the equator, but there would be very little seasonal change.

2.18  Suppose the tilt of Earth's equator relative to its orbit were 10 degrees instead of 23.5 degrees.  At what latitude would the Arctic and Antarctic Circles and the Tropic be located?

The Arctic Circle would be at a latitude of 80 degrees N; the Antarctic Circle would be at 80 degrees S.  The Tropic of Cancer would be at a latitude of 10 degrees N; the Tripic of Capricorn would be at 10 degrees S.