I'm going to have to look further into this one... the gas could be related to the food you are feeding. What are you feeding him?
As far as itchy skin... yes ferrets normally have dry skin that causes them to scratch a lot... however if your house is too dry it will intensify it for them. This is why it is said not to over bathe them (however I believe they can play in the water as much as they want) & when you do bathe them use a good ferret or kitten shampoo with good conditioners in it!
I'm sure Nancy will come along with a little more information on the male scent issue as my male does not have this problem.