First I must say that I am a cradle Catholic, I have been Catholic my whole life and my family before me, for as far back as they can be traced, were Catholic. I left the church for a time and I am back now so I know about some of your issues.
Praying to Mary was something I used to think about myself and wonder on...
Now, after seeing The Passion it feels like I got to know her a little bit. Can you imagine what she went through that day? Also think of it this way, she carried Our Lord Jesus in her belly! This is the most blessed thing one can do! You must understand that our prayers to her and not directed to her alone, we ask her to pray for us. I know that Jesus loves His mother and so I know that her prayers for us will be very powerful. It falls in line with the prayers of the righteous. Who, other than Jesus himself, was more righteous? We honor her greatly because she is the mother of God.
As for The Pope, I know that people were hoping to just fall under Peter's shadow hoping they would be healed. So in a sense this is sort of how Our Pope is treated by some and if he is a succesor of Peter, this does make sense.
About Priests; I think it is very cleansing confessing our sins to a priest and I do know that it is scriptural but someone here will have to provide you with the exact scripture. I know that Jesus gave The Apostles the power to forgive sins and our priests, through apostolic succesion also have that power granted. I am not sure if I am explaining this properly so I will wait on someone else..
All in all I will say that even with any questions or concerns I may have, I do hold fast to the fact that this is the church Jesus himself started and that is reason enough for me to be a part of it.
Not sure how much this helped...