It's never wrong to make clear, informed decisions about just what you can and cannot handle with your pets. You will be happier and the rats will get the attention a pet rat is used to....a win win in my book hon.
Funny about that study. I certainly don't pretend to be all knowing about temperment and coat colors but my experience is directly opposite from what you are saying that study found (I'll make time to read it fully later today). Every self black I've ever raised and kept has been a bit on the nasty side temperment wise, every agouti has been a lovely rat with good production litter wise and a nice, stable temperment. I currently have no self black rats anymore. My agouti's are Charlie, an agouti male and Gracie and Betsy ButtPatch, agouti and white hooded (mismarked though as far as anyone can ID their odd markings for me....funny they are almost identically marked though totally unrelated LOL).
I will say I'm less than impressed with minks. I currently have two females, Gabby and Freda who are just way overly hyper and difficult to deal with. I had another Patches who wasn't much different though a tad calmer. My only mink that I really like to work with is Dee, our mink dumbo...she's a very nice rat.
All of ours that are retired are considered pets. They still live within the colony as that is their social group and they still have their little "jobs", tending the maturing group of young rats destined to be future breeders, keeping other oldster rats company, even running herd on a group of weanling feeders if they need the calming influence of a mature rat of the same gender.