1. Why are spellpower criticals being reduced by a factor of 3?
2. Will both trees be able to take them? Will both trees be able to use the full rune arm enhancements?
3. Are class capstones being done away with?
A couple of comments:
1. I'm worried that linking spell power to rune arm charge is a good idea, but a bad plan. It produces optimal times to fire off spells - that certainly adds role-playing flavor (omg, my rune arm is so full of energy, I can tap that!), and will limit how and when artificers spell cast.
2. Reducing the spell crits chance so much greatly decreases the burst damage output of the class. Only if there is a corresponding increase in spell power will the class be able to contribute as much damage to party tactics as they currently do. Admittedly, managing aggro is a bit of a challenge (but fun) and so if damage output remains the same, you might be making the class more user friendly.
3. For me, the current, live artificer capstone defines the class. Its removal - and the separation of rune arm enhancements in one tree, spell power and crits in another - suggests that the class will lose a great deal of its versatility. It feels like it's being cut in two and I have difficulties imagining that it will be as enjoyable after.
One last point to consider: trees have roots. The core abilities of classes should perhaps be in a "root" from which the trees build off. Doing so would put all the general and class-central enhancements in one place, able to be taken by both tree lines.