You can start here for acronyms and definitions.
wiki/index.php/Category:CPAP_Definitions
Do you have the clinical/provider manual for your machine? It has even more definitions and explanations.
If you don't have it you can request it here.
http://www.apneaboard.com/CPAP%20Adjustment.htm
Down near the bottom of the page are the directions for requesting it. Be sure to request the machine by its proper name...PR System One Auto CPAP with AFlex.
One of our forum members has a blog about Encore Viewer software which is same data but different software.
All the way down near the bottom..
http://maskarrayed.wordpress.com/
This should get you started so you understand what you are seeing.
Your minimum appears to be 4 cm and not 5cm per this report.
This report is quite acceptable. AHI is less than 5 (which is a common standard) and leak line isn't nearly as dramatic as it might look due to reporting scale. Educate yourself then come back with specific question about what you are unsure of and someone can offer more specific ideas.
I may have to RISE but I refuse to SHINE.