I find that a lot of the lack of clarity comes from a cultural disconnect. Most readers do not take the time to understand what the NT letters meant to the original readers. For example, "the elements will melt with fervent heat."
I believe to the original reader it was obvious that the elements referred to here are the elements in the temple. To an NIV reader, we think he is talking about the periodic table ceasing to exist. Do you think the cultural disconnect is a problem, or that modern english translations are basically self explainitory and can be read at face value?