Fire Fighter is a very difficult trade to get in the CF. I believe part of the problem is that there are far too many graduates of fire fighting programs at colleges across the country. As I understand it, it's also a difficult job to get in the civilian world. I know of an applicant to the CF as a fire fighter who had already unsuccessfully applied to 10 civilian departments.
"From what I understand you are "scored" so this means that even though someone has been waiting for a year or two merit listed, a new recruit could be up higher on the list even though he has only been merit listed for a few months by his higher score?"
Correct. Selection is generally based on merit(score), and not simply on a first come basis.
If it is what you really want, hang in there but expect to wait. How long of a wait is difficult to say, it could be more than a year.
Good Luck.