I can' t think of any other good museum you should visit. Taking a slow stroll along the town center appears to me as one of the best ways to enjoy the city. Alternatively, try the bicycles taxis run by former unemployed. A flea market is organized every Friday and Saturday morning at St.-Jacobs. Office hours are 9-17 on weekdays, perhaps open longer on Thursday evening.
Most machines takes EC- and usual credit cards.
The neighborhood of the theoretical Math institute is a bit boring. There is a Vietnamese restaurant Tanh Lih in the Zwijnaardsesteenweg which is by far superior to the Chinese restaurant next door. They offer plat du jours for 250 fr, and are associated with the Riz d'Or in the town center mentioned above. You could try the Vietnamese chicken curry, which is prepared with fresh chillies and lemon grass. Books Most are expensive, due to high taxes.