I transfered the option files in 2 parts, using a USB stick.
I don't think it is the same option file you spoke about though, i'm 99% sure I don't have any N-Power Championship teams.
I've unlocked 950/1000g with the option file on my xbox, and played 20 odd online games - no ban, no warning etc.
However, I have no idea if it is actually 100% safe or not. I have seen lots of ppl online saying they are using patches, and none of them have reported issues.
Hope that helps