So, to further report on this odd behavior,
After further investigation, the brightness with auto-brightness seemingly drops light output further than the "0" setting in my brightness app, and further than the slider allows manually adjusting via the settings>display panel. Odd.
I disabled all auto-brightness via the settings in the TouchWhiz apps (read: the browser and the video/audio player), and was just controlling brightness via the app I installed.
Later today, i turned on auto-brightness again via the Power Saving widget, and the issue where the screen dims farther than any manual settings allowed was gone. Again, i only have an issue with max brightness now-- using both the system settings panel to adjust brightness as well as using auto-brightness via both the power saving widget as well as the system settings panel.
So, in summary: the max brightness issue remains, and i can only set it to about 80% without using the brightness app i installed (the app allows me to set it to 100%....where as in the system settings, the slider goes to 100%, and stays at 100%, but the screen looks like its at about 80%. Using the brightness app i installed allows me to boost it back to 100%, but as soon as i change the brightness in the system settings app, or the power saving widget, it maxes out at 80. The slider moves all the way to 100%, but i'm only getting 80% brightness).