all sounds pretty normal for a 20+yr old car.
rubber seals get hard and start to leak.
coming from the top of the engine, should only be cam cover seals.
the gearboxs wear 2/3/4 synchros, so thats normal.
brake and clutch fluid are easy ones.
and the steer rack leaking, how bad?
the engines are pretty tough.
if not taking it to yhe track, the short nose crack isnt that bad.
mine withheld 4yrs of spirited driving.
ended up failing due to oil usage and me not checking the the level.
if that happens, save your pennys, and throw in an r34 motor.
or, if going for big power, rebuild.
either way, youll end up loving the car.
dont know a gtr owner who hasnt.