I agree that Snake wrecks TL, but there is no death grab, even if you tech chase him on reaction with 100% consistency, it still doesn't guarantee death at all, or even 0 to death %. It is still completely sick though.
On Snake's weaknesses, IMO DDD is the only 40:60 or worse, I think Snake may lose to more characters than is normally thought, maybe I undersell him but I honestly think he's overrated, but mostly by very slight degrees, DDD is the worst and only one I'd bother picking up a secondary to deal with if I were a Snake main.
I think Snake beats ROB though, his camping isn't that hard to get around and he can't really gimp or combo you like Wario, MK, Marth, DDD, Falco etc. can unless you're making mistakes. He outspaces your first hit ftilt but the damage and KO differential is massive, and ROB has difficulty landing his kill moves as it is.