It will only take you so far, and it shows in the teams international performance. You can't just play like you're playing MM or something when you're at the top. And he has shown inability to actually accept criticism and guidance, instead always coming up with ****** excuses for his ****** plays.
Not always a good idea. If he chose to unscope , the guy could likely still get those shots off into his head before he could shoot, and even if he did to beat him it'd likely be a no scope, which would likely miss.
The knife however? I've seen someone go for what looked like a perfect knife opportunity in a pro game and it backfired horribly.