Questions about the blacksmith class

Specifically about customizing items. I just need to know a few things.
1. Does your proficiency in blacksmithing have any effect when you add stats to an item?
2. What thoughts go into statting? How do statters determine what stats to add and what to remove to increase the item's potential for more stats?
I know I'm probably making myself sound like a dumbass but I'd really appreciate it if someone could just give me clear answers. Emphasis on the clear, since I don't really do well with answers that go all over the place.

 

1.nope
2.its kinda complicated, it involves some kind of penalty if you add a stat that has same category at once, that's why you add a stat little by little, look for a Statting thread for more detail. Just use the proven formulas if you don't want to calculate yourself. I believe there is also a statting simulator on coryn club site

 

** NOTE CREDITS GOES TO WYRIX FOR THIS**
You receive a penalty multiplier when adding from the same category.
("Number of items in the same category" squared, multiplied by 5)
2=20%, 3=45%, 4=80%, 5=125%, 6=180%, 7=245%, 8=320%, 9=405%, 10=500%
*Potential is always rounded down (example: 10.9=10pot)
*Penalties stack & carry over to the next step
*Do note that multipliers can work for or against you.

Every substat inside each category is classified as being from the same category.
For example, if you were to add atk+7%, then later add matk-7% m.pierce-3%, this equates to 3 substats from the same category (Enhance Attack), which brings about a 45% potential penalty. Adding cdmg+7% cdmg+11 would add another 20% penalty, bringing your overall total to 65% penalty.

from 150cap thread