Thank you for the reply Brandon. I believe "Telligent Community" or "Telligent Community Server" is the new, re-branded name for what used to be called just "Community Server." I am only concerned because we use such an old version of it and I do not see any reference on this site to the versions that can be converted.
A 4th question if you have time:
(4) Can we employ some kind of single sign-on method? We will be using Umbraco CMS Version 4.7 and that could make things simpler, I think.