WPA2 cracking is usually done with rainbow tables generated based on some dictionary and its mutations, basically don't have a dictionary password and you should be secure from /most/ attackers.

Your passsword should be made up of dictionary words though. If you do the math an 8 word sentence from the 10k most common words (just lowercase) is equivalent to a 16 character password from a full set of 100 characters and far easier to remember. Use some exotic words and punctuation and have a few random special characters in there and it is far far superior. WPA2 has a minimum of 8 characters and would take the same time to check every character as it would to check all combos of 4 lowercase words from the 10k most common set.

WiFi passwords aren't typed in frequently and can trivially be written down on the home router itself, CorrectHorseBatteryStaple has lower entropy than a random one of a bit smaller length.

Wifi passwords are typed all the time if you have any friends that come over. And typing randomly generated special characters on a mobile device is especially awful.

No, they aren't if you create a nice QR code for people to scan.

You should have your friends on a guest network instead, have this on a DMZ, and tell them to use a VPN over such guest network.

Rainbow tables aren't really applicable to WPA2 due to the way offline cracking is done.

You would have to pre-generate them for each possible SSID. You're much better off using a small targeted dictionary with rules.

You are absolutely correct, it's usually indeed dictionary-based but there are rainbow tables as well http://www.renderlab.net/projects/WPA-tables/

As much as a tutorial on how leaving your front door open lets burglars in your house.