1. You cannot post Raw to the web, no matter what size you shoot, it must be converted to a Web format like jpeg, Gif, etc. During the save for web process in photoshop, you set the final size.
2. The main reason I would use SRAW would be if I had a underpowered computer, or was running out of storage space.
3. Nothing wrong with using it though, a P&S would do as well, if you just want to shoot for web.