Velvet is shown by a spread of soft looking reddish or orangish spots that run together, from the pics it does not appear to be velvet.
For ich treeat at least for ten days using the heat and salt method, less is only partly effective and will often result in reinfection.
The thinness is most likely a result of a long term protozoal infection such as hexamita, this is generally shown by white or clear, slimy feces and is best treated with metronidazole laced foods.
Parasite clear do not treat ich but does contain metronidazole although it is an external application and so less effective than the foods. It can treat hexamita but is not guaranteed to do so. The long term effect of an internal hexamita infection is a slow thinning and loss of disease resistance due to malnutrition.
