The bangs might be the oleo's bottoming out. Also when the pilot selects gear up the wheel brakes are applied to stop the wheels spinning in the bays. (Causes an annoying vibration). The pressure used is a reduced pressure but it still might cause the wheels to stop with a bang. I'd still go for the oleo's bottoming out though!.
The dogs barking in the rear hold is the sound of the Power transfer unit (PTU) working.
( A hydraulic pump driving a hydraulic motor so that in the event of one hyd system failing one of the other systems can power it!)
Rgds Dr.I.