Passive Voice agression

While I was preparing to post today, I was stuck by the idea of writing about passive voice. Recently I was able to read several samples of writing. It was fun. It was enlightening and they were full of passive voice. The tone of the works were varied and the content was very different, but the sentences were so often in passive form that I was pulling my hair out over some of the paragraphs.
In fact, while writing this post, I was fighting with the urge to scream.

Not claiming to be an expert on active voice or passive voice, I am merely going to pose a few questions and give some examples from when our group studied passive voice vs active voice.

How many of you noticed that the first paragraph of the post is completely passive? How many of you are bugged by it? When is passive voice a good idea? When is it lazy writing?

Some teacher out there can explain how the verb 'Be' makes a sentence passive etc. I'm just going to say, if you do a word search for "was" in your manuscript and find 8 uses in one paragraph, hopefully you did it on purpose and not by accident. If it was an accident, then changes are easy to make.

It was a dark and stormy night. (passive)
Dark thunderclouds rolled across the sky. (active)

I was alone in the room. (passive)
They left me alone in the room. (active)

Times to use passive according to our guru on grammar:
1) When you are describing ongoing movement or action. (ie: I was curling my hair, when the phone rang.)
2) To break up an intense scene or stream of action: (I can't make up a good example cause I keep trying to fix the passive.)

So when do you think its okay to use passive voice? Is there a difference from 3rd person to 1st person? Does it vary by genre?