Having put my Time machine drive on the finder sidebar, I find I can now access the drive and open files directly from a backup without navigating through the Time Machine App/Restore facility.
Yes, that's normal. Time Machine stores your stuff as regular files and directories and hard links (which look to Finder like regular files and directories).
As far as I know, it's OK to copy (drag) files from the TM backup to wherever you want, instead of going through the "starfield" interface. However, do not delete, move, or rename any of the files on the backup disk -- you'd risk "messing up" Time Machine's system. Be very careful about that!