I was wondering about what the "commenter's" and the "characters" are.
Commenter rankings are based largely on the number of replies you've posted on the forum (vs author, which is based on new threads posted and their popularity). Unfortunately there's a bug such that the commenter medals go to the authors (I should have the #1 commenter medal, but it's on Frogboy instead).
Character medals are just based on the rank of that character (you can have up to three) in the metaverse, pretty simple.
because I have had the same one (#3) for both 5 and 20 game winner and only the mouse over changed when I went from being a 5 game winner to being a 20 game winner.
Where are you seeing this at? Under your posts there are both #2 (5 games) and #3 (20).
The naval ranks are based on a combination of games posted and score, AFAIK. I do not know the specifics, beyond that more games with more score makes for higher rank.