credit report

What is the name of your state? Washington
Is it practical of me to think that I can get an old creditor to remove or improve a report they put on my CR? Especially if the debt was paid yrs. ago.Also, what is the best way to go about doing this without lessening my chances of success?
I'm also having trouble understanding my reports as well. For example, not all of the reports on my CR have a Date Open,some reports say N/A.What do they mean not applicable? There are some reports that have the wrong date open, by 2 yrs to be exact.Is this a way for them to keep the debt around a little longer?
One more thing,how do I find out when a creditor actually posted a report on my CR? The 2 year account activity graph from experian is kinda confusing me. Plus some of the reports don,t even include a two year graph.Can anyone offer up a little advise on how to understand my CR a little better? Thanks