You dont call out if the enemy completes items etc?
Na maybe an early dagger but most of the time no one reacts to such calls anyway.
I don't think so. I usually need to suggest a strategy, item, or priority and that stuff doesn't really do that.
For instance, suggesting, then justifying that your carry buy Diffusal against Warlock or Omniknight.
That´s so much hassle that you probably can´t even focus on your own game and i bet you get ignored most of the time anyway.
I found that when i let them do their stuff and just play it´s not only less agrivating and often it works out.