How Light and Dark Arts affects your effective skill and skill cap when you sub SCH is a little complicated. It took me a bit of time to figure it out. I posted my finds in this thread: http://ffxi.allakhazam.com/forum.html?fjob=20&mid=1236892005281431015&howmany=50
Short version: there is a bottom threshold that Arts will raise your effective skill if your natural skill is below it, and you will only have capped skill (blue numbers) with Arts up if the skill was already capped without Arts up.
I noticed that when I used Dark Arts, I was still getting skill ups for dark magic, but my magic level didn't increase. How does this work?
Your native dark magic skill was actually increasing. But because it was below a certain threshold, Dark Arts pushed up your effective dark magic skill (the number you see and the number that gets used in calculations) to what you were seeing. Once your native dark magic skill reaches a certain point, you will see that number increasing as you get skill ups. Edited, Feb 19th 2011 10:40am by svlyons
Lyonheart of Lakshmi
lvl 99 NIN WAR BST THF BLM SCH WHM
1/467 on signed HQ Weskit!!!