SJS, I agree with you. I think (and I may be wrong) that the main idea of tefilla is to develop a relationship with God. So, if that would mean telling Him how you feel; angry, happy, hurt, confused, etc., then I believe that you are fulfilling the purpose of tefilla. Yes, one still must daven with a minyan, 3 times a day, at a certain time (with a hat?) and all that.
~a~