What are the steps and considerations for applying for a 12-month marriage extension in Thailand?

On Wednesday I will be heading to immigration (Chaiyaphum) to apply for a 12 month extension based on marriage. I have 2 questions:

1) Is this the application form we need to fill out(?), and if not, please can someone send it to me?

2) I've been told officials will probably come to the house to inspect and verify we live there (though there was no mention of this when my wife phoned them up). I know this will vary from province to province, but do the officials usually give you notice of when they are going to visit. The reason I ask is because my wife and I both work, meaning neither of us will be home during the day from Mon-Fri, plus my wife works nearly 40km away from our home. I'm thinking of re-registering my residence to my wife's family home (also in Chaiyaphum but a different district) where we sometimes stay. At least there, her parents will be at home to show any documents etc in case we are at work....Do you guys have any recommendations or can give some idea at how it works? :) Thanks :)