Please correct me if I'm wrong, but I thought that cooking, alchemy, and scribe exceptional were pointless since you can't make exceptional items.
It depends on what's being cooked.
Most high-skill items are possibly exceptional. Many of the mid-range items can be exceptional as well. They don't have any real effect over normal, other than retaining name of the cook, etc.
Most baked goods, pies, pizzas, miso, sushi, etc. items are craftable exceptional.
Some of the older BODs from the first 6 months or so were bugged to not be able to be bribed to be exceptional, which is a bit of an issue. Similarly, There's an issue where Flour is almost impossible to make (low quantities of wheat, and you have to use the crafting menu somehow, not the four mills, to make it exceptional).
To say the system still needs work is an understatement.