I'm no expert but what you said seems to be fine. I transfered all the flac files over and they worked fine.
The guy that suggested the tag I mentioned said the following and I think their advice was based on the best tag for XBMC to grab al the metadata and cover art when scanning.
"If you use mp3tag and add all your mp3s into it you will likely notice there is a variety of tag versions being used, ID3v1, ID3v2 (both 2.3 and 2.4) and APE, first thing I recommend using mp3tag to save them all into the same tag format of which I recommend ID3v2.3 UTF-16 which is what I use, and then remove all other types, so the files just contain the ID3v2.3 tag (ID3v2.3 is the best to use as it has support for fields greater than ~60 characters but a warning some very old car stereos may not be able to read anything other than a ID3v1 tag)"
So I don't know really, but my main concern is making sure all the albums display properly. Lastly I notice that a lot of my music shows the ID3v2.3 tag, but some show the following
ID3v2.3 (ID3v1 Lyrics3v2 ID3v2.3)
ID3v2.3 (ID3v1 ID3v2.3 APEv2)
Most are showing this ID3v2.3 (ID3v1 ID3v2.3)
So entertain the fact that I may need to convert my tags for XBMC, and tell me are all of the above shown in MP3TAG all variations of the ID3v2.3 tag but not a true ID3v2.3 tag.
Sorry for my ignorance, but this is my first time dealing with this stuff