Complex scripting isn't exposed in this release cycle, though I hope to see it open in future releases. Adobe's ExtendScript platform is pretty simple and intuitive and allows for very complex functionality in the other applications supporting it.
I'll add your notes to the Scripting feature in the database. I'd love to see us expose FFT arrays and selection control via scripting, and it's great to get some feedback affirming that.
So, you guys are clearly serious scripting users -
Also (guessing you work with a number of people cause of the we?) - do you have one or two people that generally write scripts that are used by everyone? Or, is everyone comfortable writing at least basic scripts for what they need to do?
What kind of sound design work are you doing?
"We" is the audio department of a video games studio, and I'm the maintainer of the scripts that assist us in creating and rendering our audio assets. It's not a full-time job, though, I'm also a sound designer. This is one of the reasons we're Audition fans -- there are a lot of goodies in there for us noisebenders =)
Being a coder-heavy outfit, we would have expertise in most of the languages you mentioned, with C++ being at an obvious forefront. C#, Lua and Python are commonly used in the tools, plugins and exporters we write for various applications such as Photoshop or Maya.
Vegas ships with a set of .NET binaries for its scripting API, hence it supports C# (my weapon of choice), JScript and Visual Basic. You reference those binaries in your project, thereby gaining access to a Vegas object which contains collections of tracks, events, buses and so on. It also provides methods for modifying those collections (adding markers, moving events around, that sort of thing) or rendering files to disk. Vegas can be called upon to execute a script directly on launch, running "headless" without user interaction.
I've personally taken quite a liking to C# and .NET; it gives you access to all kinds of helpful libraries, not the least using Windows Forms for the interactive parts. The scripts run in their own domain, so they have all the abilities of a regular .NET application -- including file operations and even web requests. I assume you'd want something a bit more platform agnostic for Audition, but there's something to be said for that degree of freedom.
Addendum: As I posted this reply, I was informed that I had been logged out, and hitting the "back" button presented me with an empty form. After a brief rageface I proceeded to attach a debugger to Firefox, and managed to track down the post in the memory dump. Secure in my victory, I went back to post it... Only to discover the that your forum has an auto-save feature! Well played...