If a pastor or elder in your church starts saying that they are a "prophet", or have a "special annointing", or if your pastor discards the scriptures, run away as fast as you can.
No joke.
Why does a church need the Word when they've got a Prophet???
</sarcasm>
You bring up a good point. One of the problems with the modern day "apostles" and "prophets" is how can you disagree with their "word from the Lord"? If you really believe they are "anointed" then you must take what they say at face value, no matter how bizarre that word might sound.
Also, on a more reformed note, the basic charismatic approach to worship, etc is along the lines of "whatever is not forbidden in Scripture is permitted." This follows the Catholic/Lutheran/Anglican model. In contrast, many reformed believers, especially Presbyterians, follow the rule that "whatever is not commanded in scripture is forbidden." It's called the Regulative Principle of Worship. More info is available here The Scriptural Law of Worship.