yea those look like rbp. the spots, teeth, and the way their fins are a little cut up is typical of baby piranha that lfs owners don't know how to take care of
In the very first picture that you posted the fish behind the other fish is definitely a pacu. Look at the long fins. The other one I cannot tell but looks like a natt to me.
the last set of pics you posted look like natts though but still their mouths look kind of funny for a natt. You may have a mix of them. Try to get a few more shots that are a little more in focus if you can.