The 2month paid visa is called a Single Entry Tourist Visa and is valid 90 days from day of issue.
Things did change many moons ago, you apply using this website and you will get the visa by e-mail, with the order to print and show on request bij check in and show on passport control to enter Thailand. If you want to save you visa for a few weeks later, do not show at passport control, there is nothing but only a print out.
As it is applied on line and send by e-mail a one day visit to a Thai Consulate is no longer needed or wanted.
Look for requirements for application of the visa at the Thai Embassy in the country where you are. For Extension of Stay you need minimum 2 months prior application minimum 800.000 Thb on a Thai bank account on your name. Money must stay there for 3 months after aproval date and rest of the year not less than 400.000 Thb
No, because if I count: 60 days +30 day Extension, border run for new 30 days + 30 days extension makes 60+30+30+30= 150 days, which is only 5 months. You need to do another border run to get the second 30 day Visa exempt entry to make it 6 months.
Yes, there a plenty of visa's available which will give between 60 days, 90 days, 1 year or even 5 year of stay and can be extended as long as you can meet requirements. All based on the reason why you like to stay long time in Thailand.
Most immigration offices want you to apply for the 1st Extension of Stay same as the reason why the visa is issued.
As the visa is based on marriage your 1st Extension of Stay must be based on marriage, if you divorce during this Extension of Stay, you can cancel this Extension and apply for a new Extension of Stay based on 50 years or older.
But nothing to loose to ask if you can apply directly for based on being over 50 years of age.
If you mean a retirement visa as in Extension of Stay based on 50 years of age, you need OR an income affidavit from your Embassy with minimum 65.000 Thb income a month OR if your Embassy does not provide, at least 12 months prior application a monthly foreign deposit of minimum 65.000 Thb into your Thai bank account.