James - 2.5 inches for a platy!!?? wow that would be some hugggggggge platy
yes you are overstocked, but i think its manageable. For instance, look at my 10gal. Its HEAVILY overstocked but i keep up on my w/c's and test my water alot. Havent had a prob yet and everything is fine
so you can take back a few fish if you feel it is needed, but IMO your fine
I think some people worry way too much about overstocking.