This will not hide or remove your full history of connections. It will change your MAC so you'll look like another person who lives at your house and works with you. But the published list of networks remains the same.
Wrong. It probes without announcing any networks, and compares the list it gets to the list you have saved. If it finds a match, it then probes specifically for that network without announcing any others it knows.
The main drawback is that it doesn't work on Windows (wpa_supplicant on Linux already does this by default); on my laptops I just remove all networks when I am finished with them - entering a 15-20 char password every couple of months isn't so bad, especially as I only really use my laptop when travelling.