Offense is more important than defense. You can't make your defense indefinitely better. There is always a limit, cause you can't win with less than zero goals against. But you always can score one more goal. It is also much easier to destroy something than to create something. So the "two-way" and "elite defensively" are simply excuses for a lack of offense.
Not so sure about that one, depends who you're comparing I guess.
I would take a 90 point Selke level forward over a 100 point player who is average defensively. I would say an elite Selke caliber centerman easily prevents more than 10 goals a year than an average one, probably closer to 20 actually.
Defense generally is easier than offense, and also much harder to quantify, but not just anyone can become a super elite defensive player because that actually takes great hockey sense and anticipation like Lidstrom, Doughty, Fedorov, Datsyuk, Zetterberg, Bergeron, Kopitar, etc.
There are guys who are responsible defensively, and those who work extremely hard at it, but some talk like that's all it takes. If that was the case a lot of horrible defensive teams wouldn't be horrible defensive teams.
I think a 76 point Toews is better than just about any forward up to 90 or so points, but in the case of Crosby 100+ is a little too much. I think Matthews could become like Toews was with an extra 20-30 points a season.