S/H, levels and curves - some doubts

[Duszolap]

Hi,

After reading a tons of material about photography, photoshop I've got a mess in my head - of course I've learned a lot thanks to sites like this but there are still some unresolved problems I can't understand.

First, all my questions are related to Photoshop CS4 to be specific and all photos I take are RAW.

There go my doubts and questions

1. As far I know Curves and Levels are very similar tool (of course Curves give us more control) - so it IS possible to recreate identical setting with both tools. In most of tutorials and guides they are recommended to adjust photo parameters. However there is also....

2.Shadow/Highlights - that tool made my first doubt
My questions here:
- Is that just another interface with the same possibilities as Curves?
- Is it possible to recreate exactly the same effect using S/H and Curves
- Should it be used as alternative to Curves or as additional tool?

3.Camera Raw - with all those sliders similar to S/H (but named differently - Blacks etc) I only got more confused so here i got a question too:

- What is recommended workflow with Camera Raw?
Edit Exposure, save an image and edit the rest in Photoshop (with Curves and/or H/S)
OR
Edit photo completely using Camera Raw and ONLY this tool - skipping Photoshop.

As I am novice PS user from my point of view some settings are doubled thus making me hard to understand what should I use to make most of my photos.