where are you finding these pics? That is one righteous old Tecumseh.. Your clutch is pretty amazing itself.. You don't find them like that anymore..
They put your muffler that way from the factory, but yeah if it is burning your leg, you could always loosen the muffler and aim it down or in another direction.. You can extend it some or just screw the muffler into the block without the angle..
You don't want a big ole hunk of pipe in the motor, as the weight of it can break the block or wear out the hole if there is no bracket to hold the extra weight..