Your friend is pretty ignorant to say such things, he obviously has very very little knowledge on how PA works.
No that is incorrect. Especially against blinkers or magic immunity or invis targets. Your SnY and blink won't help you. Late game if there is an AM with MKB + basher what can you do? that's why turning it into abyssal is very important later on. Itemization is very important and it varies from game to game and draft from your team and opponent. You sound like a D1 player "Burzia" should never be picked on PA because she already has a 350% crit chance and that shit won't help. I am not sure how you guys analyze things. Pretty amazing.

I don't think there's a fix way of playing in D2. D1 yes maybe but D2 no way. I've played and seen a lot of rigid players. They will always buy the same item regardless of situation.

Whether basher is useful for PA or not will solely depends on your team mates and opponent. Learn to buy item depending on situation. The so called "pro" who says a hero must buy this and that really are