Welcome to FT. You may want to consider separately carrying your laptop then it will not count towards your weight limit. As to how strict is SQ regarding this issue, not strict at all unless you are going to India, China, Philippines, and generally anywhere that has got a ridiculous amount of hand carry taken on the plane. It also depends on the airport. E.g. FRA is quite strict from my experience. The airport personal weight and make you put your bag through this frame to check its size before immigration.