I can just picture it:
car drives into a dark alleyway and stop. A hooded figure approaches
"psst over here"
"you got the kitten?"
"you got the money?"
you hand over a small suitcase full of small bills
he hands over a wrinkled paper bag with a cat in it
you give a slight bow and get back into the car
he fades into the shadows...
The world of pure-bred cats is a confusing and baffling place for first-timers. It was for me too. I have to say though, I'm not sure I agree with your lessons learned. Like Ontariobengals mentions, early neutering is actually a pretty desirable thing, and usually a sign of a diligent breeder (since it's an extra cost to them). Also, for me I wouldn't put much stock into reviews when it comes to selecting a breeder. It's very unlike buying a blanket on Etsy or a piece of memorabilia on ebay. And quite frankly I care a lot more about how they raised and bred their kittens more so than the transaction itself, or whether they offered me a lot of support after I took the kitten home. There are a lot of objective things to look for though, and there has been a lot of discussion about that here.
In terms of the cat that you got, yea, at this point, like you said, the manner in which you got him isn't really that important. He's your cat, and a very handsome kitty, and sure looks like a bengal to me!. Take good care of him and love him. You'll get no criticism of him in this forum. He needs a better toy though
Check out 'dabird or neko flies. Also getting him some approved things to climb (like a tall cat tree or shelves) is also a great early purchase for a bengal. Have fun!
Welcome to the forum.