When I sing, usually only 1/2 songs amongst friends (or down my local club), or more at "Filk" weekends. I will sing traditional songs as I remember them, or as I have the words written down.
If I am singing my own songs (Filk), then the words are usually not offensive.
If I am singing trad songs, I take no responsibility for the way the songs are written, but convey them to (possibly) a new audience. I don't believe our modern sensibilities should give us the right to censor old songs.
Many people are unaware of the verse of the English national anthem which offends the Scots, and do not realise that "The Sun has got his hat on" included the line "He's been tanning niggers down in Timbuctoo; Now he's coming back, to do the same to you". These lyrics will be lost to the aural tradition if they are not ever used. The appearance of the full lyrics in the DT do not mean that they are passed on in the aural tradition.
Surely if we feel we cannot sing a song as written we should sing something else, rather than 'Bowdlerise' the song.
This is all, obviously, my personal opinion. But I do not consider myself racist/sexist/homophobic. But few people do see themselves in those terms!Nigel