As long as we don't trade him, I think we could work out a Philly type of situation with him where he doesn't retire but goes on permanent LTIR until his contract expires. He gets his $$$ and the Rangers can spend the cap. Win-win.
You're assuming Richards suffers a career ending injury like Pronger and Savard. What if Richards remains healthy but just can't play anymore? Then what happens? The NHL will never allow the Rangers to put a player without a career ending injury on long term IR AND leave him there for years.