Whats wrong with a common fish? hmmmmm... maybe because EVERYONE in the world has one or knows what it is? I would rather have people say "wow..I never seen these types of fish ever..Kewl tank!" . instead of "oh..yea..I had that type of fish when I was, like 5".
Groups= You can say 5 you can 7, or you can say 3. The group should not have an even amount of fish. 3 is an acceptable ammount as as the lowest number you should keep.
Rosy barbs as nippers? dont believe me? Mine went after the cories and never stopped harrasing them untill I got rid of the rosies. I got them when I first started the 60 gallon. After that, no more coomon fish for me.