No I have not yet had any problem with the Danios and the cichlids.
The cichlids really hand out at bottom mid range, and the danios chill out at the top of the surface and are fast swimmers. That am I keep my crew well fed, so there is no desire to eat the small danios. The one LFS around here charges $6.99 each, or 3 for $20 basically.
Most puffers, specially dwarf puffers, really do best in a species only tank, they are emotionally sensitive (in concerns to other tank mates) and they can be terrible fin nippers, to the point where the other fish die.
I just rearranged my 30G a little, so I will take a picture of that tank as a whole soon enough.