verbs - perfective vs. imperfective

[david-us.livejournal.com]

I ran across this sentence and translation in recent studies:

Кто читал эту книгу -- поднимите руку! 

"Those who have read this book - please raise your hand!"

It seems to me that since a completed action is implied that прочитал would be more appropriate.

I would translate the sentence, "Those who were reading this book - please raise your hand!"

I am continually surprised how often Russians use the imperfective verb form when a completed action is clearly implied.

And, I am still totally befuddled as to which verb to use (imperfective vs. perfective) when making an imperative. Generally, I use the imperfective with a negative infinitive.

For instance, how would you say?

"Wait for me!"
"Don't wait for me!"

David Emerling
Memphis, TN