What does partial trust mean the Web Part developer?

If an assembly is installed into the BIN directory, the code must be ensured that provides error
handling in the event that required permissions are not available. Otherwise, unhandled ecurity exceptions may cause the Web Part to fail and may affect page rendering on the page where the Web Part appears.

Does a SharePoint Web site include search functionality?

Yes. SharePoint Team Services provides a powerful text-based search feature that helps you find documents and information fast.