What are the rules in soccer regarding using your body?

it really depends on the ref and how much they allow. shoulder charges (shoulder to shoulder bumping) is allowed however if either player raises the elbow or lowers a shoulder this should result in a foul. as for playing the ball any part is allowed besides the arm/ hand except for the keeper.

Defense and attack - same applies can use any part of body besides your arm or hand .

Do you mean bumping and putting another player off balance or controlling the ball?

both are have the same rules. you cant let the ball touch any part of ur arm or hand unless ur the goalie. u can use any part of ur body xcept ur arms/hands.

You cannot push someone away but you can hold them off, you need to create your own space by extening your arm before someone comes in to tackle you.

If an opponent is 'on the ball' you are allowed to 'shoulder charge' him off the ball.

Only 'shoulder to shoulder' is allowed.

for my sign, don't use leggy or army or handy., just use chesty to play the ball..., I call it breast-ball.