Thanks for the link Sabine. I used to play Irish Pubs and similar gigs for a living. I think that Solingen's was just one more which I won't do again! That's not an anti Irish thing folks, it's an anti IP thing - which is very different. Maybe we should get in touch Sabine and swap some contacts.
Wilfried's town is on the way up, Marion (Köln is well North of München). It would involve a detour, but it could prove profitable - and anywhere is a better bet than that ghastly hole Frankfurt (no offence intended to holes)! Brussels is two hours from Köln and three hours away from the lovely town of Brugge. Holland can be very interesting (it's also within striking distance of Köln) but you won't make much money busking there.
The centre of Prague (like Dresden) is breathtaking, but much of the rest needs demolishing. If you go to those cities, you should set out from München, because they are a long way East of Köln. They were both quite buskable when I went there.