Re: Steering
I think there may be several reasons if you think about it, the idea that a lone drivers weight will counter balance the prop's torque makes sense, but so doe the fact that most people are right handed, meaning that they can use their right hand to control the motor while they steer. It may well also just be that since most boats are set up this way, it only makes sense to standardize control boxes and steering layouts.
I have had a few boats with left hand steering, one was an old Owens, another was a 1961 Glaspar Avalon, which I've seen built both in left and right steering. The port side wheel on the Glaspar made things interesting when trying to fit a later style Mercury control to the port side gunwale. The original twin stick Evinrude controls would mount either side, but the 1987 Mercury controls would not having the lanyard and center button on the lever pivot on the left side of the controls and only one way to route the cables. It made me stick with an older Evinrude on that boat.
It may also have a lot to do with public perception of how a boat should be these days. It never made much difference to me which side I sat on to drive but I'm sure there are some that would find it hard to adapt.
I have seen a few center console boats built with the steering towards the left side of the console, meaning that the driver doesn't sit dead center, but off to the left a bit with a passenger seat to his right. My Bayliner Trophy was that way, as are many large console boat with the controls set on the right side of the console.
While it's probably just personal habit, I prefer the motor controls be to my right, my Duratech has its controls to the left and the seat dead center, I can't wait to change that when I put in the new console.