Is there any way to verify individual FLAC files against the accuraterip database?
Yes. Cue Tools will do it.http://www.cuetools.net/wiki/CUETools_DownloadSimply navigate to the folder the files are in, tick the 'Verify' option and hit 'Go'. Then watch as it does it's magic.
Coming Soon: Check Individual Tracks (currently PerfectTUNES AccurateRip can check complete albums, tagged or not)