Cheap mobile plans in Belgium

No. Discount brands and virtual operators resell capacity on the same three physical networks as the premium brands. The radio signal in your street is identical. What differs is the customer service, the shop presence and occasionally the priority given to traffic at peak times in very busy locations.

If you have wifi at home and at work, a few gigabytes covers messaging, maps and music on the move. Video streaming outside wifi is what consumes bundles quickly. Look at the usage figure in your current phone's settings before choosing, since guessing usually overestimates.

Generally yes, under the European roam-like-at-home rules, but the fair-use limit applied to the roaming portion of a small bundle is correspondingly small. If you travel within the EU regularly, check the roaming clause rather than assuming the whole allowance travels with you.

Yes. These plans are usually sold without a minimum term, and number portability is free and handled by the incoming operator. Start the switch with the new operator and never cancel the old contract yourself first, or you will lose the number in the process.