consider mo din yung size ng sensor. kadalasan di na tinitignan ng mga tao yung size ng sensor kaso importante din yun. full frame dslrs have 1/1 sensors. most of the dslrs ngayon nasa 1/1.6 - so cropped na sila. yung mga point and shoot mas maliit pa dyan. a 10mp point and shoot would have more noise than an 8mp dslr.
research. go for the one with the higher megapixel + large sensor.
as for the optical zoom, pwede ka namang lumapit.