CC:
@boundless-energy-78552 to help with the issue you are seeing in 1.
For 2. The scope is to run on every platform that libwebrtc runs on. That includes all of the platforms you are targeting with the exception of Web. That's excluded from the initial phase of the project due to the number of differences in the WebRTC stack, especially variances across browsers. Eventually it'll be a nice goal to abstract over that platform too in Rust, but that's not a goal for v1.
In terms of scope, we plan to include media devices support as well, where the Rust code will integrate with media APIs on each platform. Ideally, you would be able to compile the Rust SDK for each platform and it would "just work"
3. timeline is hard to predict.. but it should work today for receiving videos.. publishing support is being worked on as we speak. PR
here if you are interested in following along.