Join Mudcat Erica - it's free and takes a minute - and then send me a PM. I live in Cologne where busking is effectively banned now, but I have been to a lot of other places. What do you need public liability insurance for? Are you doing fire and glass? For most shows, the ordinary private general accident insurance "Haftpflichtversicherung" should be perfectly adequate. My insurance office is just down in the village, so I could nip in their and find out for you.
BTW, the NZ radio presenter John Greet - formerly known as "New Zealand John" has vast experience of busking Europe. You should contact him for some all round advice.