You will probably need 45-ratio sidewalls or the tires will rub the fender linings in tight turns.
Super-soft tires on the street are OK if you don't care about spending a ton of money on replacing tires. They might be a little noisier, but if you get wet/dry ones, they should be fine in the rain. As far as steering goes, if you have a good alignment, you should be fine. It will be a bit more responsive, though.