Most of the kicker steering attachments are quick release. So no issue with raising or lowering or whatever. I tried one for a bit and still ended going back to just the tiller for 2 reasons - 1) I seem to spend most of my time at the stern working the downriggers and lines, and 2) I can still use the IO for a rudder. Works well enough for most tasks when trolling,
If you get a new motor, they are a lot more effective/efficient than the older motors. You'll want a 6-8 hp maximum for current production high output outboards on an 18 foot boat.
I got a 10 horse '84 Honda 4 stroke. It putts along at about .8 mph at idle. That is perfect for kokanee. If I was fishing for almost any other type of fish I'd be looking for 1.2-1.5 mph as my minimum and could use a bigger more efficient motor. But the Honda serves well and I figure it will still be ticking away long after I'm able to enjoy it.
You must get a 4 stroke for trolling, 2 strokes don't like idling for hours at a time. Don't get carried away about HP with newer model high output motors unless your kicker is also your backup power out in the ocean. The smaller motors do a better job of quietly putting along at the speeds you want for most game fish in fresh water.
I plumbed my outboard right out of my fuel water separator filter. Put the primer bulb inside my engine compartment and a quick disconnect fuel fitting on the stern right by my motor mount. Plug in, pump a little and off we go. I stuck a 6 gallon tank in the ski locker as backup fuel and have never used it.
Rick