Most of these you already basically answered yourself.
There is no need to use RLM as you built your website in RSD. However if you want to make a quick wireframe/prototype for a mockup website, RLM is the perfect tool.
2. When do I use Bootstrapper?
If you want to build a website using the Bootstrap Builder framework.
When you want to build a website in RSD....
4. When do I use Foundation Framer?
When you want to build a website using Foundation framework
5. When do I use Responsive Slider?
When you want to create a responsive slider.
6. How exactly do I integrate Color Palette Manager?
When you want to share palettes between any responsive app. Color schemes you setup in RSD could be used in Foundation Framer.
? Expounding more...
