1. instantaneous.
2. I get the context menu instantaneously too, see image, or do you mean when you select Scan 'area' ?
3. If you mean when you select Scan 'area' it is pretty much instant and the scan starts and concludes very quickly.
If yours is anything less then, you are likely to have some conflict going on, what other security software do you have installed or what are your system specs like (one of the many reasons we keep harping on about signatures it saves us asking every time) ?