I'm not planning on supporting return type inference since I actually don't like that feature of TypeScript, but I could be convinced otherwise. It really harmed API readability for me when I tried to use it.

All declarations in ThinScript are order-independent right now so classes are accessible everywhere simultaneously. I'm getting away with that because I'm currently requiring all global initializers to be constant. One idea I had that would allow for non-constant global initializers without really complex static analysis to determine initialization order was to initialize non-constant global variables on first access instead of on startup.

I chose "int" because I was aiming for familiarity with existing languages. I'm also planning for WebAssembly to be just one target among many targets so I don't want to align too closely with WebAssembly. Some other targets I'm considering are C, x86, Swift, and C#, for example.