I agree completely. Screw the Rangers.
As far as Stepan goes, it's really not too much of a gamble though. Even if he never improves, you're still getting a 50 point, top six center, who plays great defense, for the prime of his career. And you'd only be paying him about a million more than his actual value if he never improved at all. A 50 pt. guy, at Stepan's age, is generally worth 5.5 on today's market, so it's a mild overpayment if does doesn't improve, and a quality contract if he does. It's not like they're paying for potential here, he's already a very good player, they're just overpaying slightly under the assumption that he'll take the next step.
I'm always happy to slightly overpay for a good player, rather than slightly overpay for an unproven guy. The risk seems less.