Here are my opinions:
1. Read live_vol's threads- he often references if he feels there has been a "buy" or a "sell" - he has legit reasons for his beliefs and you might learn something if you study his threads.
2. Why does it really matter to you in most cases? If someone buys 1000 calls, does that mean you want to? Maybe, but you shouldn't assume if you just knew if a trade was a buy or a sell all of the sudden that it would do you much good.
3. I see this argument/question all the time in the penny stock world as well - every trade has a buyer and a seller, but sometimes trades that go through at the bid are considered "sells" and trades at the ask are considered "buys".
JIMO,
JJacksET4