I think, TBH, you've probably already reached the point where it's going to be really hard to work well in a discourse thread. To me, it sounds like you've reached the point where you have enough of an idea that to figure it out any further you'll need to either
- Write some kind of formal proof of some property of interest, or
- Write the language and see how it goes
After all, Rust only became as good as it is by going through a rather drastic transformation. At one point it had a GC and Green Threads, famously. There's no substitute for making it exist and seeing how it does on a real problem.