Naomi - I believe that the leader of my church "leads" my church and receives revelation and direction from God just like the Prophets did in the Bible, so to answer your question yes I do believe that he has knowledge that I don't and he is God's instrument in letting us know the will of His church on earth. Now about the Spirit I would like to quote a scripture from my church (mind you this is what I believe for myself, u can take it how u will):
"But, behold, I say unto you, that you must study it out in your mind; then you must ask me if it be right (prayer), and if it is right I will cause that your bosom shall burn within you; therefore, you shall feel that it is right. But if it be not right you shall have no such feeling, but you shall have a stupor of thought that shall cause you to forget the thing which is wrong."
The burning in the bosom is the Holy Spirit revealing truth or knowledge and this is what I believe is how we receive our own personal revelation from God. This is what I did to know that my church is true.
I know many people don't belief this even though it is said in the Bible, but what if everyone prayed to God to be directed to truth and he led them to it because of peoples faith... it's as easy as that. And again that is the basis for my belief.
I'm sorry if i've been unclear before and I don't mean to offend anyone either so I apologize if I have.