So about this offsides thing. Why doesn't the whole team just stand at the opponent's end of the field? That way, everyone on the opposing team will be offsides the entire time, unless they can kick the ball into the the goal from the other end of the field, which is clearly infeasible.
You can't get called for offside in your own defensive half of the field. You therefore actually make it easier to time a run with no defenders behind you and break away clear to the goal since you have a physical line on the field to go by. It would be suicide.
Thiago123's comments