Most fluids have additives to make the trans shift smooth. Type F has about the lowest amount of this additive. I have read that Mercon V is a good synthetic alternative that is easy to find and has a similar level of friction modifier. I have been using Mobil1 5w20 in mine, but only for a few thousand miles, but seems fine.
Yup it is. That said, I know a lot of people who have switched back to conventional fluids because it shifts better, and this is especially true for people running T5s at high speeds.