1. Asset population needs to be imported. SSIM doesn't have a "scanning" feature to import this data. However, importing this data can be simplified. You can use comma delimited file to import, or you can use Nessus, Qualys or Retina collectors to automatically populate the asset table. I believe there are a bunch of other collectors that will allow automatic asset population as well. Your best bet would simply be to get a nessus scan of your network completed, integrate the nessus collector, and then once the first pull of the database happens all of your assets will be populated, along with the vulnerability information which works to your advantage with the correlation process.

2. No built in Vulnerability Scan feature. It's a information management solution. However, using some of the suggestions above would give you the ability to easily obtain this data.

3. You need to create specific "Queries" in order to gather this information using the defined criteria. Use the admin guide to learn more about creating queries but it's pretty simple for the task you have.