Can I sync CiviCRM data with Raiser's Edge?
CiviCRM has a fully-featured "API", which makes it relatively easy to get data in and out of it via a sync.  Raiser's Edge has an API, but it's an additional add-on.

If you had the API add-on for Raiser's Edge, this would be possible - though the more data you want to sync the more intensive the process would be.