Honestly I love to do a clean install of everything about once a year. It is a big pain in the ass, but it makes a noticeable difference.
If you are unable to resolve some of these issue via Disk Warrior and Tech Tool, it is probably a good idea.
If you can isolate the problem it will make your life easier. If a clean install does not help you then you know it is likely hardware. But at this point I think we can rule out the S2VR HD. Maybe you should try the Apple Store or Apple tech support.
Jared PicuneIdea Spring Editing, Inc. Denver Final Cut Pro UGGeeky Mac | FCP Tips & Tricks