Using the chat plugin as sales support

Hi there,

I was wondering what the optimum settings are (so other visitors to the site can't read conversations whilst they are taking place) to use this as a pre sales support tool for website visitors?

Also, how can i have it set so the visitor doesn't need to enter their email or login via a social site?

And lastly, what is the best way to turn it on or off so that when away the visitor knows there is no live chat help available at that time?

Thank you