If she were human I would say ruptured blood vessels (Nothing to worry about as far as I know) not sure if it's the same for fish though. I know some diseases have red spots as symptoms as well, not trying to scare you.
My logic might be flawed but I figure you could drop the numbers on the school and still have space for some other fish within it's temperature compatibility range.
You seem to be doing fine though, I have seen a lot worse than what you have. 2 bleeding heart tetras, 5 albino corys, a few ghost...
If I were you I would drip acclimate, I use a length of airline tubing with several knots it it to slow down the flow (or you could buy one of the drip acclimation kits). Also add a few drops of prime to the bucket to control ammonia levels.
This is a very interesting discussion, I don't have any issue with colormorphs, as long as they are bred responsibly, but imo the largest problem is the fish that are bred for their deformities, and hybrids. Some of these fish have a shortened lifespan, and have trouble swimming. Dragon scale...
I used that stuff to cycle my 125 and I will say, its ridiculously strong, 1.25 teaspoons would bring it up to around 2ppm, 2 teaspoons went up to 4ppm.
I would start by adding maybe 0.5 or 0.25 teaspoons and see where that gets you.
if you only kept 1 yoyo the aggression would actually get worse. Yoyos are a very active fish and sometimes their playing can be perceived as aggressive behavior.
Imo I wouldn't keep these guys in any group less than 8, otherwise they get too nippy.