When I last looked at CryEngine it wasn't well documented but to be honest, it was quite a while back. Beginning of last year I think? Things may have changed. Also it sounds like you enjoy the C++ where most people would find it to be difficult. Although don't CryEngine make use of Lua too? I can't remember.
I just always thought of Unity as easier to use. Having tons of examples, a very active community and coding in C#. My day job is coding mostly in C# after years of being a C++ developer and I just love C# to bits. Plus Unity has an asset store that's just great and speeds up development time tremendously.
I must admit though that I'm not that familiar with CryEngine and that me thinking that it's a difficult engine may be completely wrong.
I like your plan of doing things in steps. Lots of people want to do everything at once. It sounds like you are under control though. And in the end it's all about having fun.
