Sounds really cool. I don't play Pathfinder but I buy the GameMastery Cards obsessively and have always been impressed with their quality. The Pathfinder Adventure Paths have always sounded pretty cool though.
Your post is particularly interesting to me because I have been running and playing L5R for the past 10 years now, and I have to say it is my favorite RPG of all time. However, coming up with new plots after all these years can be tricky. Nice to know Adventure Paths might offer some solutions.
The other thing I wish L5R had was more support product like the aforementioned GameMastery Cards. I custom made my own L5R version of the Plot Twist Cards, but something like the Item Cards would be nice (excited for Jade Regent!).
I wonder if any of the other Adventure Paths would be well suited to conversion. Thoughts?