I don't know where you can find written documentation of Freddie's interviews (although I'm sure if you just googled it you could find some!) But if you go to youtube.com they have a lot of good Queen footage. Interviews, live events and stuff like that. I'm sure you could find at leaat a few good interviews ... but remember Freddie didn't really like interviews/the press so there arn't that many!
Good luck and I'll let you know If i find anything!