That's just implementing a static type system in the dynamic language.

"2) I like the style of passing a thread to every function. In that case, I wonder why you even have globals that multiple threads need to access. What I try to do is initialize ALL shared data in main(). And then pass those structures ONLY to the exact threads that need them. This can be done in either static or dynamic languages; it enforces a nice structure and is easy to read."

I code much closer to that when latency matters less. As it stands, reshuffling different views for different functions takes precious nanoseconds every function call.

Edited to add: My response to 1 should not be interpreted as "BAM! Point for statically typed languages!" My contention is that statically checked type systems are phenomenally useful - this really just weakens the notion of static or dynamic types being a fundamental attribute of the language. I think a more accurate perspective is that for any language and any type system, there is some subset of the language that abides by the type system. That intersection may or may not be useful, and may or may not be checkable, but the most joy is to be found where it is both. The only real wins from integration of that checker with the compiler are 1) it's unavoidable (which can be relevant if you generally have sloppy process, but fix your process), and 2) the type information may provide invariants useful for optimization.