Seems odd to me that insurance is the same for vaccinated, not vaccinated, and does matter which vaccine. If some are more effective than others and any is more effective than none, shouldn't risk affect cost?
You will not likely find legal work as SEO/SEM specialist. There are a few reasons for this. However, you could possible work from home, freelance, and not tell anybody.
"I want to eventually generate some income " - I would worry about that after you've gotten accustom to the situation here in Thailand. There are few options for earning money all with different affect on your visa situation. If you plan to open a business then you have some visa options, if you plan to work for an Thai employer, other options. For a foreign employer more options.
Things are very relaxed here. If you come on a retirement visa, enjoy yourself, figure out how you plan to earn money, then look at the visa options available to you.
I think its the "certificate of entry from a Thai embassy " that I need to be concerned with, do you have good source of information about what's required? Insurance? Quarantine? Booking requirementes?
The answer to the question is.. TransferWise (now know as "wise"). You will need a bank account where ever you are, and she will need a bank account wherever she is. It will probably take a couple days to set-up.. but then transfers take a few minutes, I think the fee is $9.00/USD + 1% or something, you'll have to check yourself.