Was the gimbal bearing shot? If not, you just wasted money. And no, not 'good insurance' at all. Just putting money in the shop owner's pocket. I have several of my customers with gimbal bearings over 20 years old. All still in perfect condition (thanks to proper and timely maintenance) and not looking like they'll need to be replaced any time soon. And exactly the same goes with shift cables. If it's not worn or tight, it's perfect, and doesn't need to be replaced 'just in case'...
Boat ownership will be expensive if you keep replacing things that do not need to be replaced.
Chris......