B727 First Officer reported that multiple system failures resulted in a diversion.

Narrative

Immediately after takeoff upon gear retraction GPWS sounded 'Whoop whoop pull up terrain' followed by erroneous airspeed and altimeter indications on both #1 and #2 airspeed and altimeters. Also standby altimeter appeared to be unreliable; about 3;000 feet error. ATC advised mode C on transponder was also in error so stopped squawk on Mode C.[We then] asked to divert to a nearby alternate. ATC provided needed vectors and separation. During final approach phase lost most of A hydraulic system but were able to extend landing gear normally.At 1;000 feet GPWS again gave warnings - 'Too low - Flaps' but we were properly configured and on glide slope. [We] made a routine landing [but] engine #1 and #3 thrust reverser failed to open.