fill out all the required information and send. The confirmation of the successful registration and the issueance of password, by immigration, might take any time from 2 hours to 2 days or in some cases 2 weeks

alternatively you can register for the online filling out of TM30 . .

If it his his first time, I would recommend they both visit immigration, and yes HIS passport is required plus the TM6 card

no appointment required at Immigration. depending on your area and the frequency of visitors, you may have to expect some waiting time if there is a queue

normally you have to register a new TM30 within 24 (and some immigrations 48 ) hours after your arrival from abroad

most likely the house is registered to your Thai wife. She will have a "blue housebook" in Thai that is proof she lives there. Your wife, her ID card and her blue housebook and you must visit the immigration office which serves your area, and register a new TM30. You will have to bring your passport and the TM6 departure card which is stapled inside your passport

thank you very much for a valuable information at just this point when so much about the O/A visa or Extension requirement are unclear. Thank you

if you plan to come back with your METV before January 29th, in the hope that you can convert it inside Thailand into a Non-Imm-O based on marriage, you should ask your Immigration if they are willing to do the conversion. Not all Immigration offices will do it

If it is a Multi Entry Tourist visa what you got, it will remain valid for the said period until January 29th. You cannot apply for a new visa in your home country as long as you still hold a valid visa in your passport. You can however start the application process for the Non-Imm-O based on marriage right after midnight of this day, from 30th of January on

You are lucky and very clever to have had a Thai national translate it for you, as number 5 just means that if you already receive a pension, you should supply document evidence certified by your embassy. Otherwise if you go the 800,000 deposit method and are over 50 years old, these documents are not needed