id agree you are about at ur limit.. i have a 28g nano too i started out with 2 clowns, a blue tang, and a flame hawk.. all 1 inch babies but after awhile they got aggressive with each other.. eventually the blue tank died for what ever reason, so i got a six lined in its place was a great worm eater for the first couple months and he was scared of the smaller flame hawk lol so i moved the flame hawk cuz he wasnt benefiting my reef and he would poach food from my corals.. then when i moved him to my brothers tank the six lined got aggressive and would chase both my clowns around the tank so i moved him to my brothers tank also so he can go back to getting bullied but some how the six lined and flame hawk get along now (what the heck? lol)... then my 2 clowns were getting along so great and all of a sudden one morning i woke up and the smaller one was dead.. then the clown left got really aggressive and would attack me non-stop when ever my hand would breach the water, so i moved him to my girl's new tank.. and recently i picked up a randalls goby and a "randalls" shrimp (really a totally different species) i bought them at a LFS as a pair already in the same tank but they werent actually paired but rather just placed in the same tank.. so i eventually took the annoying pistol shrimp (that liked to shoot me!) out, but ive fallen in love with my randalls goby!! never getting rid of him, recently converted my tank to inverts only besides they goby...
so the moral to my story is do your research and ask questions.. sorry for the long story, hope it helps.. nice tank by the way =]