I think you can successfully migrate to vim modes by using less than optimal vim habits initially. I don't think anyone is going to go through the entire action list and instinctively remember all of them, and be able to use them at a moments notice.

As an example, my transition was something like this: I'd use a vim plugin, and use say 5- 7 basic actions + movements like `cw`, `c$` `i`, and keep it limited to that for a while. If you're frustrated, simple insert mode (`i`) is all you need to get back to your comfort zone. Pretty soon, you get those ingrained, and then start looking for other tricks to learn. A few years later, it's second nature and you're probably slightly more productive. Bottom line is that it shouldn't take you 2 months to break even, hopefully.