Each Thai embassy sets their own requirements. So go to the website of the Thai embassy that you want to apply at and see what their requirements are. Someone giving you an answer means nothing because they might not have used the same Thai embassy that you will use.
The difference is that there is no such thing as a 1 year non-O visa.
There is a 90 day non-O visa. It has no insurance requirement but requires you to show you have 800,000 baht or 65,000 baht per month in retirement income. It is single entry. Then there is a 1 year extension you can get from this visa that has similar requirements but you'll have to show the money in Thailand, and it is zero entry because you're already in Thailand when you get it.
A non-OA is a 1 year multiple entry visa. The multiple entry means every time you enter Thailand during that 1 year, you receive a 1 year permission to stay stamp. This requires a high level of health insurance, a health certificate, a criminal background check, and you can ONLY get it from the Thai embassy in your home country. You show money in your home country bank account to qualify for this visa, and it makes very little sense to ever try to extend this visa in Thailand because then you'll have to show money in a Thai bank account AND you'll still be required to have that high level of insurance.
Sure, if you're from a country eligible for Visa on Arrival and you come without a visa, you have to apply for and pay for a visa at the airport. Otherwise no, you don't pay anything at the airport.
They are real tickets. They are either unpaid reservations that self-cancel if payment is not received or they are fully refundable tickets that the agency refunds after a few days.
No one HAS to get a visa. But if they want to stay in Thailand with you they will need to have their own visa. As Thailand does not recognize civil partnerships, they would have to qualify for their own visa and apply for their own visa.
know personally? No. But I've talked to the owner of the agency while he's been helping people with that service and know it works. They will check everything after you submit your request and if they cannot get you through the airport they will tell you.
I don't think it's unreasonable to expect someone to have a plan to leave a country only 60 days out when that's as long as their permission to stay will be valid