Very interesting! I'm also implementing a programming language for my undergrad dissertation (but specifically for agent based simulations).
The thing that struck me most about vector was the radically different for loops (compared to C). I'm assuming you're purposefully crippling them to make parallelisation easier? Or is there another reason?
EDIT: One other thing - the website fails to scroll nicely on a mac (in chrome). I had to manually use the scroll bars instead of being able to 2 finger swipe...