Couple question regarding pick list


I have several questions when I using pick list module.
First, when I create the pick list from work order, the item locations table listed the items mentioned in work order which actually come from BOM
I don’t know the exactly meaning between Qty stock Qty and Picked Qty.
In my snapshot
Column Qty , Column Stock Qty and Picked Qty seems all same.
In my understanding,
Qty = How many I need in this work order
Stock Qty = How many I have total in warehouse
Picked Qty = if amount of stock qty is less than qty, how many I can use for pick, normally equal stock qty.
Please correct me if I’m wrong.

Second, if system told me some of items don’t match the requirement like this.
How can I quickly create the material request form?
Right now I need to write down the item code, create the MR form manually. I mean the whole process is manually, I may make mistake like inserted wrong item code in MR form.
So is there a way that unmatched item can be listed in new MR ( Material Request ) automatically ?

Thank You