If it's (5), the stalling speed you see should be roughly the declared stalling speed x the square root of (Actual weight divided by MTOW).
M14P - increased g should increase the stalling speed, not decrease it. On the other hand, less than 1g during a slightly greater than necessary descent should decrease it.
Another factor I forgot to mention is deceleration rate. The book figure should be for bang-on 1kn/s, a greater deceleration rate should give a lower stall speed, and a higher deceleration rate *may* give a higher stall speed.
G