To kick things off here’s what I’m up to. I’m interested in learning Rust because I think it will be a useful skill, particularly around the SAFE Network. This has begun now because I came across syncer, which is written in Rust and I’m trying to modify it to work with SAFE. I managed to do that, but found I can’t get it fully working without some extra features being added to the SAFE CLI, and am learning more to see if I might have a go at them.
To learn Rust, I’m reading The Rust Programming Language (see the OP), which is an excellent book and a very good way to get up to speed fast if you already know a systems language like C++. I’m a little over half way in a few days, have made quite a few notes, and getting to the hard bits 
Before that I had a look at the SAFE CLI code and realised I would need to understand Rust much better before thinking about modifying it.
I’ve got a development environment set up in VS Codium (the privacy version of VS Code), which makes working with Rust very nice, and saves a lot of the work in catching errors, formatting code and helping me find what I need all in one place. And it has a built in source code debugger. 
(Here’s a topic on using VS Code with Rust)