Certified GA aircraft will have met a design requirement similar to or as this:
Sec. 23.203
Stall characteristics.
(a) For level wing stalls--
(1) For an airplane with independently controlled rolling and directional controls, it must be possible to produce and to correct roll by unreversed use of the rolling control and to produce and correct yaw by unreversed use of the directional control, up to the time the airplane pitches in the maneuver prescribed in Sec. 23.201(b);
(2) For an airplane with interconnected lateral and directional controls (two control), for an airplane with only one of these controls, it must be possible to produce and correct roll by unreversed use of the rolling control without producing excessive yaw, up to the time the airplane pitches in the manuever prescribed in Sec. 23.201(b); and
(3) During the recovery part of the manuever prescribed in Sec. 23.201(b), it must be possible to prevent more than 15 degrees of roll or yaw by the normal use of the controls.
(b) For turning flight stalls, when stalled during a coordinated turn with 30 degrees of bank, 75 percent maximum continuous power on each engine, and flaps and landing gear retracted, it must be possible to regain normal level flight without excessive loss of altitude or uncontrollable rolling or spinning tendencies.
(c) For limited elevator control stalls, it must be possible, when stalled from an excessive climb attitude, to recover without exceeding airspeed or acceleration limits.
Note, in particular, point 3. This is for power off stalls, power on, will introduce torque, which will require extra attention to rudder use. Without applying unusual pilot skill and attention, this should be achievable. If you're having trouble making the plane stay within these limits, and you're applying proper skill and technique, you should be looking for a rigging error with the plane. There will be rigging adjustments possible, though for that plane I don't know what they are. It would be common for a rigging error to appear as a cruise flight problem as well, but not always. Following a rigging adjustment, a test flight with stalls will be required to verify.
You should be comfortable stalling - well, all pilots should - but particularly for this testing. If your plane is mis-rigged, then stalls at altitude will be great practice for you! Remeber, when you have planned stalls at suitably high altitudes, it is not necessary to minimize altitude loss during recovery, let it descend, and build a little speed, then recover, you're not in a hurry. In a stall, or incipient spin recovery, the nose pointing down is good - flat is bad, let the nose go down.
I have maintenance check flown many planes with either known, or I found stall handling deficiencies. It's not great that they get this way, but that's why we check.
Every plane for which I have flown a post maintenance check flight, I have stalled several times, just to confirm handling. I have found some horrendous handling defects, one in a brand new (3 hours TTSN) plane - that was a manufacturing defect, and failure to detect during production/acceptance test flying. The plane spun violently, no matter how precisely it was stalled. In that case, I found and reported the defect. The owner's pilot acknowledged it, after flying himself, and then before returning the aircraft to the manufacturer for rectification, killed himself and another person in a stall spin after takeoff. The "evidence" was destroyed, so only my report remained to prompt the investigation. Stall handling defects should be corrected without delay. Though you can compensate for stall defects, when you most need the plane to behave, it could let you down badly.