Typically ellipses
No, not all planets have elliptical orbits. While most planets in our solar system have nearly circular orbits, some planets, like Mercury and Pluto, have more elliptical orbits. Additionally, exoplanets outside our solar system can have a variety of orbital shapes.
Kepler discovered the orbits of the solar system are elliptical.
Yes, everything that orbits our sun, including everything that orbits everything that orbits our sun, is part of the solar system.
No. Pluto orbits in our solar system.
A moon orbits a planet.
The heart is the star around which the solar system orbits. In our solar system the heart would be our sun
circular
By definition all planets in the solar system orbit the Sun; also, in order to be a planet they have to be large enough to achieve their rounded shapes.
None of the planets pass out of our solar system. The orbits of the planets, irregular as they may be IS the solar system.
Yes, Earth orbits the Sun in our solar system.
Yes, the Earth orbits the sun in our solar system.
"Gravity" is responsible for the existence of planetary orbits, and for their shapes and periods. It's also the reason for the spherical shapes of the planets, and for the existence of atmospheres, in the case of those planets that have any.