I met a girl called Miki (not sure of how she spelt it) at a childrens birthday party recently. She's 13. I did ask if it was short for anything and she said it wasn't but everyone asked her that. I like it and it suited her too. I have a friend called Michaela but she gets called Kayla not Miki. Nice name and lovely idea to use your Dads name.
I was at school with twin Chinese girls called Me (yes really - got me into a lot of trouble when the teacher asked "Who drew on the table?!" and I replied "It was Me, miss"!!!) and Miki. They're both very traditional oriental names. If I saw the name Miki I would always pronounce it Me-Key, whereas Mikki would be Mickey. I guess it depends if your bothered about your dd having to correct people all the time or not. Maybe it's just me but Miki wouldn't ever be pronounced Mickey.