Well, you need to do some research. "Blue fish" is not a specific kind of fish. It could be anything. Puffers will rip your swordies and probably all of the other fish in there to pieces, not to mention that the only strictly freshwater puffer you can put in that tank is the dwarf puffer, which gets only about an inch long. DPs should be kept with other DPs for the most part. All other puffers that you could fit in that tank, or even buy, are going to be brackish or marine. Freshwater flounders are actually brackish too. African clawed frogs, which are sold in an albino variation, need colder water than tropical fish. ACFs need between 70-75 degrees Fahrenheit, while tropical fish need around 80. You won't be able to keep any of those fish you just listed.
Edit: Depending on the species, some freshwater flounders only grow to 4". Still brackish though, so a no to a freshwater tank.