If the wallet keys can be stolen, then it is like an account changing hand

That's true. In crypto , it is said that not your keys not your coins.

organization to buy an asset, push its price up, and then immediately sell it.

I have been victim of this scam myself and i know how innocent investors are screwed by scammers.

The link is like an intermediary for us because the real party is a third party. I later went back and asked more experienced ones, and it turned out to be a spam comment.

Yes suck spam links are often seen on beginner posts when they aren't well versed with the platform .

Good luck