Good ideas, I did a bit of that, but will do more.
Don't be in a big hurry and keep looking.
Just like that "perfect boat", you'll eventually find the "perfect trainer."
He/she/they may not be "professional instructors" by some standards, but you'll know them when you meet them. Personable. Confident not cocky, experienced yet humble. Give me an instructor that spends a lot of time talking about themselves, and I'll probably be looking for someone else shortly.
When we do intros at my courses, mine is about 30 seconds. On occasion I've been known to say simply, I'm Gordon, been an instructor for 30 years, here to help you get better at what you do and stay alive...period. We can (and usually do) chat a bit more over lunch or between strings if safety allows. Some of the leads at other places I teach get a little put off by it, but all that other crap is pretty much fluff. Show me what you've got. The proof is in the pudding as they say.
As far as knowing "your" boat, I wouldn't worry so much about that as I would knowing the systems in general. Every boat, like every car, motorcycle, aircraft, etc. will handle differently even if it's the same make/model. I've proven this through many years as a motorcycle and tactical driving instructor. And even when I was learning to fly it bore true. Same Cessna 150, different tail numbers...and there would always be "something" different. The basics are there, but there will always be little idiosyncrasies that set it apart from another.
Just my buck fifty on the matter. HTH
OD