Carry-On Ques: If policy says 1 carry-on, and 1 pers item like laptop bag, can I bring backpack for pers item?

You most likely will be able to use the smaller backpack as your personal item. Most major airlines allow a 45 lineal inch (h+w+l) carry on bag plus a personal item such as a laptop bag, purse or small backpack that is no more than 36 lineal inches in total size. The website you provided doesn't list the dimensions of the backpack, but if it's no more than 36 lineal inches in total size, you should be fine, especially if you're using it as a laptop bag.