I am still scratching my head a bit on changing the timing belt. I can't see what kia uses to align the cams. I can, however, answer your second question. The reason they suggest doing the water pump at this time is because it is located behind the timing belt. Because of this it only makes sense to change it when you do the belt because you will have the belt off anyway. If it goes out shortly after a new belt has been installed then you have to redo the entire procedure that you have already done. Take my word for it: spend the money and do the job correctly the first time.
I asked the personnel at www.thekiapartsstore.com when I was ordering the parts for a friend, very helpful, and actually qualified, not what you're going to find manning the phones at any other kia retailer.