first off, I think the ranking system is great. My idea to improve it, is to include some kind of chart so you can tell how high your rank is. because if your like me and havent played in a long time, you otherwise wouldnt know if your rank is meant to be really high or really low. just an idea. Either that or include names next to said rank to differentiate it from others (names like "sargent" or "corporal" or alien ranks like "deacon" or something). just a thought.
I think it would be nice to show your time played in online public matches. That way, some people who are really good and got to the last level really fast would stand out, while someone who's very bad and eventually get's to the last level...wouldn't.