1 = loose power steering belt
2 = duff motor , mechanism .Try taking door card off and bang motor whilst pressing switch (ignition on obviously).Has car been stood a while ?
3 = no idea without viewing,could be rust on outer or inner edge of disc only coming into play when brakes applied,if pads and discs are low they can grind on the lower edge of pads where rust builds up around the centre hub part of the disc .