The next stop in Belgium on my summer busking tour was Liege.
After arriving there in the late afternoon and checking in the local HI Youth Hostel I went on to do my research for a nice busking spot on the next day. I found a couple of walking streets right in the center of town that would seem to do just fine. On the one, called rue du pont d'isle, there was an abandonned shop location wich seemed just about perfect, at the crossroads with another street. Acoustics seemed promising too. So I decided I would try this spot in priority the next day, provided that it would be in the shade in the late afternoon.
Busking was good, a bit better than in namur, and I must have made around 35 euros for a bit less than two hours busking. I never do more than two hours per day really because of my voice: I have no amplification and it can get quite tough on the voice singing in open spaces like these, above a cajon, a tambourine and a guitar ;-)
So anyways I would recommend busking in Liege, in either one of the main walking shopping streets. Once again I didn't enquire about a permit or anything but it was ok, I didn't meet any police or anything and had no complaints from local shops, so that' s good!