I haven't tried the Adirondack Rail Trail yet. It's just 10 miles in length and not worth a 4+ hour drive. I've been waiting for additional sections to be completed before making the trip.
Some information on the trail is available here:
https://www.traillink.com/trail/adirondack-rail-trail/ You need to be a member to view the trail map (It's worth the the price BTW), but you can read the description and trail reviews for free.
There is also the 16 mile Bloomingdale Bog Trail near Saranac Lake. It's pretty rough, but it might be worth a look:
https://www.traillink.com/trail/bloomingdale-bog-trail/
In any case, May thru June is black fly season, so you may want to wait until July or later to make the trip.
I ride many trails in NY with my class 2 bike, and have yet to be questioned. I don't call attention to myself by riding like an idiot, and I'm always respectful to pedestrians and other bikers. As a precaution, I printed out this image and covered up the Class 2 label on the bike, using a piece of clear packing tape.
View attachment 175895
Yes, it's deceitful, but I can always plead ignorance and say the bike came from the dealer that way. I hate breaking the law, but I adhere to it's spirit by not using the throttle, except for emergencies, and always use the pedals.
As for disconnecting the throttle, I'm not sure it would make a difference to some enforcement officers. It would certainly demonstrate that you were trying to adhere to the law though.
I rode the Lamoille Valley Rail Trail up near St. Johnsbury a few years ago. It was pretty rough and there were a few bridges missing. I've read it's been improved a bit though, have you been up that way?