1. I heard nworks collectors are pretty resource consuming, so depending on how large your environment is and how busy they are, installing other products on the same server may not be a good idea.
2. Veeam Business View install SQL Express, or you can point its setup to an existing SQL. There are no dependencies on SCOM or anything else.
3. Completely independent product, so no dependencies on nworks. But Monitor, Reporter and nworks integrate with it. So think about Business View as a standalone plug-in enabling other Veeam products to do more.