I've made a few minis. I like to paper piece them for accuracy. I draw them up in EQ7, then print them out in whatever block size I want. I did a log cabin once where the strips were 1/4 inch, and the blocks finished at 2 inches. I did sew the seams at 1/4 inch, but trimmed them to 1/8 when they were done.
The only time you need to consider if your mini is "officially" a mini is if you're going to enter it into a show. Each show will have requirements for each category. Otherwise there are no rules!