Minimum octane- I don't honestly know, as we just have 95 and 97 in the UK.
I would imagine BMW have this to run as low as 91 safely, which is available in Europe, although 95 preferred. Once tuned, I would expect 95 to be safe, 91 to now be below limits
and to be avoided, and 97+ to have some benefits under harsher conditions.
Safe Rev limit is 6800-7000. I don't have any fuel consumption figures unfortunately.