I also wanted to use Street Magic as the basis for Shugenja magic. The system as presented in the 4th Edition rulebooks jars a bit for me with the descriptions of what actually goes into casting a spell. Street Magic rewards preparation and makes it part of the story. That preparation helps to make magic magical and that's what I want to capture in F5R. More detail on magic in a future post.
The biggest problem I have with skills though is keeping it simple. My formative, post D&D years were spent playing MERP and Rolemaster. For me squeezing the most out of character generation was part of the thrill. That tendency to over-complicate, (I once worked out the size and weight of every item in my thieves kit), has stayed with me and stymied all my previous attempts at game design.
So I've tried hard to keep this hack tight and not introduce too many new skill selections. There are a whole heap of new stunts though which is rapidly becoming my preferred way of building out uniqueness in characters.
I think I'm rambling now so I'll finish up this post with the list of skills and then link in a doc with the long versions.
The long version is here: Fate of the Five Rings