Re: coverting to remote steering
ohmybad -- with respect to the stop switch, I had the same challenge with a console retrofit into a 14 foot Springbok aluminum boat. The motor was a little 7.5 merc with no ignition switch or electric start, etc.
I removed the stop switch from the engine and mounted it up at the console (in the remote throttle housing, where the the ignition switch would have gone). Then I spliced some wire and ran it all the way back to the motor and in the same access as the throttle cable. The stop switch hole in the motor I plugged with the blank I took out of the remote (identical size!).
The entire setup worked like a charm until the weather broke down the wiring insulation. Easy fix, that. Next time I'll protect it better.
These are terrible pictures but they give you some idea. In the first one you can just see the engine stop switch in the red box where it's mounted in the remote's key opening. Sure, ya gotta climb back to start up, but shutting down after you dock is a breeze. Also, it never hurts to be able to kill the motor at any time on demand...
And here is the barely visible stop switch hole plugged with the blank from the remote.
And, what the hey -- the view from the helm under way at a blistering six knots or so.