Re: How far have you gone?
Thus far, I've mainly used the toolkit to create characters and games. It's fun just to recreate something you've seen in movies, in a book, or even a video game. Essentially, I've used the toolkit to model different types of games.
As for adapting the rules, I think that's possible in any system. However, Hero does a great job of being modular. If some rules just don't work well, then you can skip them (for example, optional combat rules). As it's said in the book, there's a lot of internal logic, so it would be simple to add in new elements or to customize things to your liking. The feeling I get fro the system is that you can take what you like, use it adapt it, and make it the core of just about anything you'd like. I haven't changed much, just taken what helps. I haven't played much yet (I will soon, though) but I do plan on having fun tweaking things a bit as campaigns progress, and I look forward to it.