"What person would have the skills of Sewing, Blacksmithing and Cooking?"
If you could learn all of those in game, ALL OF THEM. There apparently isn't any downside. And given that you're character is requited to eat, and you can taste the food, why wouldn't almost everyone not have the cooking skill at least?
This guy doesn't seem to be too keen on how to maximize gold/hr. If he was doing this to help skill up he'd be putting restrictions on the type of items he would make so he wasn't wasting time on times that wouldn't help him skill up.
Just more masturbation over how super awesome and unique the MC is for no apparent reason. Zzzzzz....