NP is just like C9 was, when they're not being retarded they could beat anyone. NP seems to have less of those moments though, plus since EE dropped the Puppeyrage stuff I liked him a lot more.
AM can shit on him for a while, since he farms faster and mana drain ruins his day, Morphling is sorta ok, Ember can just run circles around him. As far as supports/offlaners go, you really can't beat 6slotted slark.
Depends, I think it's worth it especially when you have no other invisibility on your team, the investment the supports have to make into detection is not small and they have to work out who carries it, especially when you are ganking with only 2-3 people. There's some overlap with blink dagger, it extends your initiation radius, but both are aggressive items, so they make sense when you know you are fucked in the late game.Watching G2 of Escape vs. Liquid, I really think that pro players overvalue shadowblade for cores other than Slark. Its like a ticket to irrelevance, they invest at least 6-minutes of farm into an item that doesn't help farm and without completely stomping will never pay for itself through ganks.
Even if you need the break from silver edge going for it early on your #1 seems to never work well.