The amount of gravity is not really quantifiable, but the gravitational force of a planet on a standard mass at a standard distance is proportional to the planet's mass.
The other planets do have gravity.
All massive objects (including all planets) have gravity.
my inability to go to other planets. and gravity
All planets are affected by the gravity of other planets.
A fair amount, though it depends on the distances of the planets and their masses. The important thing is that the gravity (and therefore mass) of the central sun must be much greater than that of the planets, other wise they would orbit each other (or the sun would orbit the planet if its mass was much greater).
No, gravity holds planets in orbit around the sun because the sun's gravity pulls on them. This gravitational force between the sun and planets keeps them in their respective orbits. The force between planets themselves is much smaller and mainly affects their interactions with each other rather than their orbits around the sun.
because of the gravity of the other planets around them
Simple. Gravity! The planets are dragged in by the gravity of the sun.
No. Of the planets in this solar system, Jupiter, by far, has the strongest gravity.
Yes, all planets have gravity. Gravity is a force that attracts objects with mass towards each other, so every celestial body with mass, including planets, has its own gravitational pull.
No. Weight is affected by gravity.
The planets' own gravity has made them spherical. Also there are other effects such as their ability to retain an atmosphere, etc. The Sun's gravitycauses the orbits of the planets.