I don't believe that the S5 is worth the extra money. It's a very slight improvement over the S3 but $200 more. Between those two choices, I'd buy an S3 instead and spend the $200 on extras.
RAW takes the light information before the camera has done much with it. This allows you to copy the image into an application like Photoshop and do your own post processing. The biggest benefit RAW has over JPEGs is that you don't lose any quality when you save a RAW file while you lose quality EVERY time you modify and save a JPEG.
If you have no desire to work on your own pictures, I don't see the need for RAW. There will be many times though that you will take a picture and be able to improve on the processing the camera did. If you have the image in RAW, it could be a stunning pic. If it's just in JPG, you may throw it away.
Unfortunately, compact cameras / non-DSLRs don't do well with low-light uunless you have a tripod. The issue here is physics. Each camera has a component called a sensor that interprets the light the lens gathers. The larger the sensor, the more processing that can be done on each dot of light. Compacts have TINY sensors, a DSLR has a sensor 12 times larger on average so a DSLR will get much better low-light shots, even before the user uses a lens designed for low light.
In the compact world, I like the Panasonic FZ-50 and the Olympus SP-550 (which I own). In the beginning DSLR space, I like the Pentax K100D.
I bought the SP-550 for a couple of reasons. It has an underwater housing, it has a superzoom (18x but anything past 15x makes the autofocus hunt a lot) and it does RAW. I needed a better underwater camera that did RAW but would be good on land as well. It does a nice wide angle 28mm where most start at 35mm. It will also shoot up to 15 frames per second in short bursts, at a lower resolution.
The effect of wide angle is that you don't have to step as far back to get everything into the frame, since you may not be able to go any further back.