Let me answer the easy one first - yes, the entire ActiveX Server interface is documented in the LV Online Help (in 8.0, in 7 I think it's called VI, Function and Online help). For example, search for "ActiveX Properties and Methods".
The restrictions on accessing LV datatypes from this interface is all about the ole automation rules for data marshalling. Use pretty much use VARIANTs and SAFEARRAY of VARIANTS to handle mapping just about any type to and from ActiveX.
When it comes to accessing this from different languages, I'm afraid you leave the world of LV and into that language's support of ActiveX. Calling LV from JScript is exactly the same as calling any ActiveX interface from JScript. I'm just not sure what you do to create a SAFEARRAY in JScript. You might want to check on a JScript newsgroup or some such to see if they can help you - as I said, it isn't a LV question but a JScript question at this point.
Sorry that I can't help you on that one. Please post back here if you find the solution. It would be good to make available to others.
