Actually, our refund policy is that if it doesn't work for what you're looking to do, after all avenues of tech support have been exhausted (i.e. our tech guys have been given a fair chance to get you up and running), you can ask for your money back. So that's something to bear in mind.
Secondly - VST has never been the most well-defined standard, and unfortunately it has not always been best looked after by its erstwhile maintainer, Steinberg. My impression is that the engineers there mean well, but the management won't give them the resources or flexibility to do things properly, resulting in the ill-thought-out 2.4 update and the widely rejected VST3. As such it's always going to be somewhat of a hit-and-miss, use-at-your-own-risk scenario with any host and plug-ins, and VST-RTAS is no exception. Coming from the high-end and vendor-controlled world of Pro Tools, that can be a bit of a shock, but let me ask - do you seriously think Digidesign doesn't have the resources to support VST themselves, or just acquire FXpansion outright, if they wanted to do so?
As to your specific enquiry re the Steinberg plug-ins - can you give me more info as to how they 'fail to open' - do they not wrap at the config stage, or do they crash, or not load in Pro Tools, etc.? Also, is your HALion Symphony the latest Universal Binary version? There are some older versions of that plug-in which are not UniBin and so won't work on an Intel Mac.
We haven't updated the wrapper much since '06, it's true - but nor has the VST2 spec or PT itself (at least until the brand new v8) changed in that time, so why would we be expected to? If it becomes apparent that an update is needed for PT8, we'll release one, but for now that does not seem to be the case although we're keeping an eye. It's early days yet for PT8, and it may take some time for the full picture to emerge on that front.