but in cruise, if the a/c approaches stall, is there any similar limitation or will pushing fwd always get the nose down ?
I doubt there is a problem in this regard because the stab trim setting in cruise is close to neutral. If the autopilot is engaged and for some reason the thrust levers have closed then the autopilot will steadily apply back stab trim until the crew discover the approaching stall situation. Even then as the aircraft is clean in cruise there should be plenty of elevator available backed up by a hasty burst of forward stab trim I should imagine.
The important point to make with regard to stalling with land flap with autopilot engaged and possibly thrust lever closed (Turkish Airlines B737-400) is that the pilot must rapidly apply forward stab trim
at the same time GA thrust is applied and nose down elevator takes place
If the pilot hits GA and initially tries to lower the nose by elevator alone he may quickly run out of elevator and by the time the nose has pitched up to a dangerously high attitude, the aircraft may stall before the pilot can get on to the stab trim. This is a important exercise in the simulator where the event is timed to take place below 500 feet and thus ground contact is imminent as Boeing say. The real danger is if someone calls for Flap 15 while near the stall as part of the GA (737). It is not a normal go-around procedure but recovery from a stall and that is a different technique.