You're right, we're missing the rationale between the design elements. Believe me, the rationale is there, we've spent a great deal of time tweaking this. Let me get this written up and posted shortly. Thanks for pointing this out.
A few specifics: Yes, the "My Space" on white background is the breadcumbs.
I agre that there are a few too many "My Space"'s on the page, but we haven't found a good solution.
We've decided to keep the bread crumb and the page title (the one right above the tabs), because these will be important for orientation on the page, so we decided that it was more important that they be present on all pages.
We could choose to re-label the tab "Home" instead of "My Space Home", though.
We have left out help icons on purpose, at this point, because we don't have much useful help to offer. We have discussed ways to present help, though, so it'll be easy to add.
As for the "My Space" at the very top, this was to address a concern about users being able to find their way back to My Space, even though it's linked from the bread crumbs, from "SloanSpace", and from "Al Essa". Plus, Basecamp has a similar link there back to what they call the "Dashboard". It's something we can easily cut, or at least tweak the design somewhat to make it less obtrusive.
As for changing colors, yes, the goal is to implement this as nice, clean CSS, to the extent that the current project allows us to do so. And we'll do everything we can to throw in a really simple color picker, as we already have a couple other color schemes in mind, and there's nothing like colors to invite for bike-shedding
Glad to hear that you generally like the design. Please keep the feedback coming.