Disney is being pretty slimy with those cuts, and are successfully fooling a LOT of people.
Disney is being "slimy"? Huh? Disney is making a kid ride. With a mine shaft, some cool looking iridescent gems, low rises and falls ideal for kids, rocks to play with while you wait, and so on... where is the slime? They're not fooling anyone. They advertise this as a "family ride". You probly wouldn't be personally interested in buying "pirate gold" at POTC either (yes the bag of rocks) yet anyone w a 5-7 year old boy knows they will immediately want them if they see them!
The awesome rocking motion is extremely minimal.
Yeah I see that... but that's ok... extreme rocking like taking banks at 60mph and swinging way out to the side would make it a thrill coaster and not a family ride.
even IF I can wash gems while I'm waiting.
Kids actually like that sort of stuff.

If it amuses them it's good for me. Not to mention, incorporating water play for kids into otherwise stifling hot lines is brilliant! I hadn't read about this... but if it's true that's awesome.
So, I don't know what to do. We may visit Orlando for a short weekend during Halloween, staying at Universal, and doing MNSSHP.
Are you talking about this as in specifically just for you? Yeah... I would say it's not your ride. One-and-done probly. If thrill is your thing why go to the MK at all? Compared to Universal, SM and BTMRR are only "medium" thrills, and the mine train will probly be "medium-light". Except for the enjoyment I will get out of experiencing it
with my kids it certainly wont rank on my thrill-meter. I've ridden every coaster at Magic Mountain, Marine World, the Great Americas in San Jose and Chicago, SFSL, Cedar Point, plus both Legolands and Universal.
You seem to be so disappointed in the ride. Keep the audience in mind. Talk to a 7-year old after they go on and they'll probly describe it along the lines of
"the epicest awesomest ride ever!"