Any of the cypress mulch substrates, like Zoo Med Forest Floor, is fine for a Red-Footed tort. From the look of the size of the tort in the picture, the moss in the hide is probably overkill but won't hurt if it is not kept too moist.
I gave up on sphagnum moss, although I know it is often highly recommended. In my case, I suspect it as contributing to a form of minor plastron rot when the moss would get too damp and the tortoises would sleep on it. I suspect it is the moss because it does not happen when I use other substrates, and the moss is acidic enough that I suspect the dampness is a mild acid.
I usually just use cypress or hardwood mulch (with no specific odors like pine or cedar) from the home and garden stores- it is generally under $3 for a big bag of the stuff.
(In my mind, almost anything I need for a tortoise, I can get cheaper and better from someplace OTHER than a pet store.)
I use regular soil and I sprinkle Forest Floor, by zoo med on top of the soil. I even sprinkle some of it outside in the tortoise garden. I wish I could get it at Home Depot or Lowe's, but our's doesn't carry it so I have to spend big bucks at Petco . Even though one of my Cherry's is big now I still pack the long fiber moss into her hide and let her dig in there. I've never had a problem with shell rot from keeping it in the hides. What you're doing sounds good to me.