tmesisTBMtmesis
Yes it is. That's why it's a foul. It's something you are not allowed to do.
Doesn't make it cheating
It's part of the game
Well it depends what you do. There's no way that putting the ball in with your hand (or an outfield player making a "save) or bringing a player down clean through on goal is anything but cheating. Being offside, which is also a foul, is much less likely to be.
Grabbing an extra ball and scoring a goal without the ref seeing and giving the goal is cheating
Committing a foul isn't