at $100 (new) you're just starting to get cameras better than tablets. If you're carrying a tablet anyway, the only reasons to get a camera would be for zoom and ease of use (tablets are slightly annoying to take pictures with due to their size & shape)
sadly, low light is sort of a problem for most point and shoots until you get to the ~$300 range.
brightness can be easily adjusted in free software on a computer.
windows live photo gallery is a free, easy to use, simple picture editor.
http://windows.microsoft.com/en-us/windows-live/photo-gallery#photogallery=overview
panasonic is one of the top brands in point and shoot cameras
the panasonic sz3 seems like it might fit your requirements
http://www.amazon.com/Panasonic-DMC-...anasonic+lumix
there doesn't seem to be ANY actual reviews about it though, panasonic has no full size samples, and flickr doesn't have anything
the nikon s9300 is also a reasonable performer for it's price (used/refurb)
http://www.amazon.com/Nikon-COOLPIX-...ds=nikon+s9300
my brother picked one up on woot factory refurb. It produces good images for a sub $100 camera. It reviewed poorly against it's ~$200 competitors (the panasonic zs/canon sx 2xx) which is probably why it's so cheap used/refurb.
some test images my brother took
http://www.flickr.com/photos/fralexandr/sets/72157634774382826/
the s9300 had a stuck shutter, but he fixed it (by holding the camera w/ lens facing down & carefully wiggling a piece of paper to get it to unstick)
the night shots are reasonable given the small sensors found on almost all point and shoots.
dpreview is a great resource for camera reviews
http://www.dpreview.com/reviews/nikon-coolpix-s9300
photographyblog.com is also good. It's not as indepth as dpreview, but it has more camera models and is easier to read
http://www.photographyblog.com/reviews/nikon_coolpix_s9300_review/