Many moons ago I trained in both acting and musical theatre - nowadays the technique and quality has dropped off through a combination of misuse, the passage of time and a lack of confidence, but it will always be my passion.
My reasons for choosing cover songs are generally just a lifetime love, or that they're flavour of the moment, or I find them pretty/sad/fitting/challenging/etc, however the mood takes me really. I have lots of my own songs hidden away in lovely fabric covered, embroidered books embellished with ribbon and sequins; they hardly ever see the light of day, through lack of courage.
I sing and write for my own pleasure and expression, and am under no illusions that my voice is anything special, or that I'm gifted or anything pompous and snobby like that. So please don't shoot me down - opinions are wonderful, and everyone is entitled to their own, but being bitchy and narrow minded just for the sake of it is more than a little pathetic.