I can't say I pay attention to how often my frogs shed, so I can't really help answer that one.
The orange cube will not be enough. Get a powdered supplement like "rep-cal" and also a vitamin supplement. There is a good dusting schedule somewhere on the forum that I will look up for you in a second.
The great thing about greys, if you don't put them through a hibernation cycle, they shouldn't become gravid (full of eggs.) So if you have a female, there should not be much concern there unless you pulled her from the wild after she already went through the season. If so, you may want to release her so that she can lay her eggs and produce lots of little baby greys. In a couple of months, you can scoop one of those up or even raise some tadpoles from a local pond.