If you kiss on the first date and it's not right, then there will be no second date. Sometimes it's better to hold out and not kiss for a long time. I am a strong believer in kissing being very intimate, and the minute you kiss, the floodgates open for everything else.
Someone able to carry on a conversation whether the topic is silly or serious. Knowing enough about life so that you always have something to say is a definite bonus.
Falling in love and having a relationship are two different things.