Okay, first thing is that tropical flakes are not betta food. Also, flakes are harder to feed in portions, are messy, and can cause bloating issues. On top of that, tetra is a horrible brand of food. The TetraBetta pellets really have no nutritional value. I would consider switching his food to something like Omega One pellets or New Life Spectrum pellets.
Second, when battling velvet, it helps to turn the temperature up to 82-85 degrees. It really should be at least 78 ideally. Also, velvet can't be seen with the naked eye. You'll see it by shining a flashlight and looking for gold colored dust, so I'm not sure what the copper color is you are talking about. I have a blue VT who has coppery gills, which is normal for him.
I also know from personal experience that scratching can be caused by internal parasites, too, which often cause bloating that seems to have nothing to do with feeding schedules.
I would wait to see Callistras opinion, though.