I personally always shoot a little wide, which gives more flexibility when cropping for different sizes and straightening the image. Not too wide, just a little. Not everyone does though so its really a personal preference.
Most people can't shoot in available light at less than 1/60 handholding, and many people can't shoot that. The general rule is that your shutter speed should be equal or greater to your focal length for sharp pics.
Absolutely try a tripod, as that may help with your soft focusing issues. I don't see getting stuck focusing on the eyes as a problem? Most people (including me) always want the focus point on the eyes so they are sharp.