All right, here is what I will do.
Going to Petco today, I will pick up a master testing kit, perhaps pop eye medication if it seems relevant with them in the one gallon and general supplies I need to stock back up on. Anything else I will need for the cycling, fish-in or fishless?
I will clean out the one gallon and move the mollies there, but I do have a concern. They are making a big change back to this old one gallon tank and might be stuck there for a while, should I really do that to them, or just euthanize? They are bigger than they were before, and I don't know if they can handle the stress.
Regardless of my choice, I will keep up fishless cycling in the larger tank. I still need to find a method for adding ammonia, if I should just add it routinely or put in a lot at one time. Do things like the filter, hood light or heater need to be running for the bacteria?
I will test ammonia, nitrite and nitrate on both tanks and do water changes accordingly. How high can the ammonia go on the fishless tank before I need to change it?
I will medicate the smaller tank they are in according to your formulas as well.
If the mollies are alive by the time cycling finishes in the larger tank, I will place them back inside.